A new standard for assets that works in real time, masters PBR, is still open and is supported by all the big names? Yes, it does exist.

According to Wikipedia, “A standard is a comparatively uniform, widely recognised and usually applied (or at least aspired to) way of describing, producing or performing something that has prevailed over other ways or is at least considered a guideline”. With this in mind, the Khronos Group, a consortium of global industry members, came together to create a standard for the real-time visualisation of 3D assets. The requirements for the standard format were a platform-independent, fast and realistic representation of products as interactive 3D objects. Last but not least, the format should also be capable of augmented reality and the 3D assets should look the same on every common viewer.

After much research, discussion and negotiation, glTF (GL Transmission Format) was chosen as the leading licence-free transmission format for the three-dimensional representation of models and scenes. In order to create a legally compliant and high-quality framework, the decision was made in favour of a certification process in accordance with ISO/IEC JTC 1. The process is already underway and confirmation is expected in the course of 2022.

Why do we need a standard for this?

In the 3D format specialist group, leading international experts from Khronos members are specifying standards in the form of glTF extensions, which are aimed at a realistic representation of materials, but also take file size, metadata, etc. into account. We will read more about examples later in the article. Even if the standards are technically correctly taken into account in DCCTools, there can be very large differences in the presentation. The worst case scenario for creatives would be to painstakingly create a 3D asset in the 3D tool of their choice, only to realise that they have to spend several hours adapting it for integration on different platforms.

To avoid this additional work, the 3D Commerce standard and the certification for 3D RealtimeViewer were created. This group includes well-known representatives from all disciplines of e-commerce, such as Amazon, Ikea, Wayfair or Target, but also from the 3D asset creation and editing sector, such as Adobe, Autodesk, Blender, etc. This new demand also provides scope for new players on the market, such as UX3D GmbH from Munich, which has launched the first visual glTF editor called Gestaltor.

How is the file structured and what data is included?

glTF is short for Graphic Language Transmission Format. It contains three-dimensional scenes and models. A glTF file contains either a glTF (JSON/ ASCII) or a GLB (binary) as a possible file extension. A GLB file is completely self-contained. A glTF file can be self-contained or refer to external binary and texture resources.

The glTF standard supports 3D model geometry, appearance, scene graph hierarchy and animation. The aim was to achieve a streamlined and interoperable format for the delivery of 3D assets, while minimising file size and runtime processing. Khronos likes to draw a comparison with the established JPG format from the 2D world and refers to glTF as “JPG for 3D”.

How does glTF differ from FBX, for example?

The main difference between glTF and other established exchange formats such as FBX is the open standard versus the proprietary approach. For example, the FBX format is best used in the environment of Autodesk products. However, if the format is required for an independent 3D real-time display on the web, mobile or as an augmented reality application, there is no way around glTF. Because it is an open standard, it is even explicitly desired to develop extensions for glTF, which are then ideally also ratified as official KHR_extensions.

What is a compliant glTF? Are there non-compliant glTFs?

A valid glTF is characterised, for example, by its official extensions, which are identified by the prefix “KHR_”. They guarantee the same understanding of physically based rendering in terms of transmission, clear coat, etc.

The following official extensions are currently published:

• KHR_draco_mesh_compression
• KHR_lights_punctual
• KHR_materials_clearcoat
• KHR_materials_pbrSpecularGlossiness
• KHR_materials_ior
• KHR_materials_sheen
• KHR_materials_specular
• KHR_materials_transmission
• KHR_materials_unlit
• KHR_materials_variants
• KHR_materials_volume
• KHR_mesh_quantisation
• KHR_texture_basisu
• KHR_texture_transform
• KHR_xmp_json_Id

A complete list for validating a valid glTF can be found on the Khronos GitHub here: github.com/KhronosGroup/ glTF-Validator.

Where are the problems with compliant glTFs in everyday life?

The challenges we often hear from 3D artists are as follows: A 3D artist creates a 3D object in the DCC tool of choice. This can often take several hours. It is all the more annoying when the artist realises that effects or information are not displayed correctly when exporting to glTF or that some proprietary functionality cannot be mapped in glTF at all. Brand owners and product managers are annoyed when the 3D viewer in the DCC tool and the viewer on the target platform (e.g. in the web shop) are displayed differently and materials or colours are suddenly displayed completely differently. Fortunately, there is a solution for both cases: simply use products certified by 3D Commerce.

The following viewers and a glTFEditor are currently certified by Khronos (as of October 2021)

• • UX3D: Gestaltor (glTF editor)
  • Unity Technologies: Unity glTFast –
    4.1.0-preview.1
  • CGTrader: CGTrader Viewer – 1.11.10
  • Babylon.js: Babylon.js Sandbox –
    5.0.0-alpha.24
  • Khronos Group, Inc: 3DC-SampleViewer

And in everyday work?

The digitalisation of objects or products traditionally begins in a CAD or design tool or using scanners. 3D digital creation tools come into play to display the result in 3D and optimise it if necessary. Up to this point, the format of the 3D object is always a proprietary format. There are some free conversion programmes or integrated exporters for converting to the real-time format. The next step is to validate the glTF again for quality control purposes and, if necessary, to optimise the size, polygon count, lighting, etc. Before the 3D object can be loaded onto the respective platform, its requirements must be taken into account. On a smaller scale, 3D artists can certainly map the process from start to finish.

The challenge begins with the generation of several hundred assets per day. Currently, parts of the processes can already be implemented semi-automatically. Many platform operators are working together with tool manufacturers to standardise and automate processes. The biggest challenges currently lie in the various platform requirements with regard to the size of the geometry, referenced material representation, quality assurance, etc. In particular, there is still no consensus on the realistic representation of materials in real time: the furniture and clothing industries demand realistic representation of wood, stone, glass, fabrics, etc. This will be all the more important if e-commerce develops even more strongly and printed catalogues are phased out, as IKEA, for example, announced in a press release at the end of last year. We expect to see a standardised solution for displaying some materials in the coming months. As an open source DCC tool, Blender is naturally widely used and is therefore very often chosen as a reference tool for exchanging formats. The Khronos Group has therefore also commissioned the development of a state of the art importer and exporter for glTF. As long as Blender supports all official glTF extensions, they will be exported correctly. To test whether a glTF is valid and all Khronos extensions work, the official sample viewer from Khronos is available at github. khronos.org/glTF-Sample-Viewer-Release. If you want to go deeper into the analysis, you will do yourself a favour by installing the Gestaltor, because an analysis is started as soon as the glTF is loaded and an error report is output in the logger.

Gestaltor

For those who want to integrate the format deep into their pipeline: Gestaltor is the first visual glTF editor that allows you to work natively with the glTF and GLB file formats in compliance with all official Khronos glTF standards (glTF 2.0 and higher) – which we have developed. In principle, the Gestaltor can be operated like any conventional DCC tool. The special thing about it is that only the functionalities relevant to glTF are deliberately included. So you can be sure: The result is always 100% glTF. No more, but also no less – WYSIWYG (What You See Is What You Get). It offers a powerful interface to massively accelerate workflows in the 3DAsset pipeline. The core functionalities are viewing, checking, editing, optimising and creating scenes. 3D content creation in standard DCC tools remains completely unaffected by the workflow. Gestaltor acts as the final link in the workflow to create a 100% valid glTF.

Gestaltor is officially 3D commerce certified by the Khronos Group. This means that all glTF and GLB files created in Gestaltor will look the same on the upcoming certified viewers from Amazon, Babylon.js, CGTrader, Emersya, Epic Games (Unreal Engine), Facebook (Spark AR), Google ( & Scene Viewer), Samsung (Internet Browser on Android), SketchFab, Unity and many others. In the private sector, the community version of Gestaltor tends to be used to open glTFs and to add or remove assets or slightly change the colour, lighting or materials. In the commercial sector, we know that digital agencies use Gestaltor for customer solutions in the augmented reality sector. In expert forums, we read that there is currently no other alternative on the market that can be used to display transmission effects in real time, for example. We usually work with Gestaltor’s enterprise customers in the form of a strategic project to optimise its use in existing 3D workflows.

Manufacturers are often looking for a way to visualise special materials or effects in real time. To this end, our experts develop a prototype in close consultation with the customer, which is then integrated into Gestaltor as an experimental extension. This is what happened with the KHR_materials_iridescence extension.

What are the next steps for Gestaltor?

One of our main priorities in the further development of Gestaltor is to always be 100% in line with the glTF standard; i.e. as soon as official CHR extensions are ratified, we aim to be the first tool to integrate them. Thanks to the very open exchange with Gestaltor customers and strategic project partners, we have prioritised some features higher or added them to the roadmap. Without giving too much away, by the end of 2021, we will have overhauled the entire UI, added an experimental CHR material iridescence extension, a sophisticated material import (pbr2gltf2) and basic animations. The ambitious plan is that we will continue to establish Gestaltor as the world’s leading DCC tool for glTF.

What is coming in the next versions of glTF?

We are currently seeing a big movement from many industries towards glTF. Automotive manufacturers are already in the process of completely converting their 3D visualisation pipelines for human machine interfaces to glTF and open standards. Representatives of standards for videos and audio files are currently discussing with Khronos sensible options for delivering this data with glTF as well. For the fast-moving consumer goods industry, there are several factors in favour of adding glTF to the pipeline. Firstly, a high-quality 3D real-time asset can replace product photography, and the official extension for metadata khr_xmp_json_ld could be used to supply all information from EAN codes to product descriptions.

What role will Khronos play in the future?

The role of the Khronos Group seems to be constantly strengthening through the development of many useful standards. With the development of the mixed reality market, OpenXR as a standard is here to stay.

Even the otherwise very restrictive Apple Safari browser is opening up to WebGL 2.0 support by the end of 2021. Games built with the Vulkan standard, such as Fortnite or all games on Google’s Stadia, are also proving to be relevant on the market. And it is not yet possible to predict what else will emerge in the direction of WebGPU. Of course, all developments in the direction of augmented reality and metaverse speak in favour of glTF, with Spark AR, Snap AR, TikTok AR, NFT in art and the digital fashion industry etc. opening up promising business models. If you want an overview of all the standards at a glance, you can find them on the official website at www.khronos.org.

What is the future of standards?

The demand for standards from major market players in all industries has become so great that even competing advocates of proprietary formats are sitting down at the same table to reach joint compromises. For us, this is a sign that sooner or later no technology provider will be able to avoid open standards. Just as USD is a valid framework for the internal co-operative exchange of 3D computer graphics, we believe that glTF is the optimal format for the exchange of 3D real-time graphics across platforms to the outside world.

What requirements for interoperable formats such as glTF will we see in 2040?

A democratic desire for non-proprietary solutions could become the norm – business models may change to the extent that users decide what they want to consume with which devices and technologies, and a requirement is established that content and usability are the same regardless of the platform. But we will see.

The post glTF – the new standard for products | Retro articles first appeared on DIGITAL PRODUCTION and was written by Bela Beier.

There is no doubt that the trackball consoles and the Editor Keyboard from Blackmagic Design are solid devices and ideally suited for DaVinci Resolve. The prices are fair, and for specialised workstations in the film and TV industry they are even extremely affordable. But what about lone wolves who are just starting out in the new world of work, or hobby filmmakers who have already had to spend a lot of money on a sufficiently powerful computer? Are there alternatives to pushing a mouse?

Blackmagic Design does not make it easy for third-party providers, because protocols for controlling Resolve are not published. This is part of the business model, as the development of the complex and powerful programme is co-financed by the sale of hardware. This is why, for example, the popular Loupedeck is not yet compatible with Resolve. But a developer from Amsterdam has taken up the challenge and programmed around the handicap. It took Glenn Venghaus three years to persuade Akai’s APC40 controller, a favourite in the music world, to work with Resolve and The APC40 requires fewer switching operations and provides even more feedback, making the functions of large control consoles accessible as far as possible. This device is durable, equipped with very precise controls and, with its numerous operating elements, requires fewer switching operations(tinyurl.com/ssm9wh6).

Addendum for the online version of this article: In the video below, Glenn Venghaus shows an update that allows the HUD to always be enabled via devices with a web browser.

But it’s even cheaper: even with a version for the small Arturia Beatstep, most of the functions can now be controlled(tinyurl.com/sm2f7y3). The small controller/sequencer from France is popular in the music world and can be found for well under 100 euros. You also need the inexpensive ControllerMate software from OrderedBytes (approx. 30 US dollars) and the Beatstep Resolve Edition. This is available in several versions, and this has to do with the type of control. The software benefits from the fact that Resolve’s graphical user interface can hardly be customised, as it has to be able to determine the exact position of the controls.

This is why there are separate versions for different resolutions and for operation with one or two screens. The Base Kit with just one version is available for 100 euros, two versions for 125 euros and the Extreme version for 175 euros includes all resolutions for one or two screens. Upgrades are also available. We tested in the standard resolution of 2,560 x 1,440 for 27-inch monitors. It is important that Resolve runs in the fullscreen window and that only the icons are displayed at the bottom of the pages without labelling so that everything has its correct place. As MIDI unfortunately does not work identically on all localised versions of the Mac OS, the author offers adapted versions of his kit. Otherwise a German system will not find the connections to Fairlight.

Installation

The first installation is time-consuming, because not only the Resolve Edition has to be installed. First comes ControllerMate and its registration. Here, especially with Catalina, you must ensure that you have the necessary rights to control the computer. These permissions must be correct, as the programme itself cannot provide any warnings. This is followed by the one-off installation of a suitably prepared open source toolkit, which is automatically downloaded from the manufacturer’s website. Now the Beatstep Resolve Edition, which is personalised for each user and, if necessary, updated for further downloads in the event of updates. Finally, you need the free MIDI Control Centre from Arturia to load the templates into the controller and configure MIDI in the Mac OS and in Resolve if you also want to control the essential functions in Fairlight. The installation program creates a RAM disc on the desktop, which you should definitely stay away from.

This complex procedure should not deter interested parties, as a detailed video by the developer explains each step in detail and even describes the remedy for operating system or Resolve errors. In addition, each start procedure checks whether everything is working correctly and issues a warning if necessary. Most of these steps are only required once anyway, as long as there are no fundamental changes to the computer or Resolve. We must also emphasise the excellent support from the developer, who responds very quickly and provides individual assistance. This is an advantage of dealing with small companies, where you are not put through endless FAQs and waiting loops only to be left helpless again at the end. Incidentally, his company is called Tachyon Post (tachyon-consulting.com) – tachyons are hypothetical particles that are faster than light.

Hardware

For the price, the small Beatstep controller makes a surprisingly solid impression. It should also be able to withstand a lot in practice, as musicians are usually not exactly gentle with their equipment, depending on their style. The first thing you should do is print out self-adhesive labels for the keys; the template is supplied as a modifiable Illustrator file and as a PDF, otherwise you would be quite overwhelmed. The software uses the key illumination for user guidance, and the respective assignment of the keys or the rotary control is also displayed when the HUD key is held down. You should largely keep your hands off the mouse and only use it for functions that are not yet controlled by the controller – and there aren’t many of those. The computer keyboard, on the other hand, can be assigned to your own preferences, only JKL and the numeric keys for printer lights should remain unchanged.

Operation

Of course, this includes the entire grading, the parameters in the inspector, most of the cut and trim functions and the controls in Fairlight (MIDI also comes into play here). But Glenn has even recently made the custom curves controllable, as well as the parameters of numerous OFX effects and even the new Cut Page in version 16 is supported (switching from Edit via A/B). Even 5 custom OFX assignments can be created with the controller and its visual feedback, but only for parameters that can also be controlled in Resolve with the centre mouse wheel. Of course, the large rotary knob at the top left serves as a jog wheel and proves to be very useful. MIDI must also be configured for Fairlight. precise when cutting and trimming. It goes without saying that the complex possibilities cannot be learnt in a day, even if the assignments reveal a clear, logical structure. The concept makes it clear that the author is not a programmer with little practical experience, but works in post-production himself. His video (vimeo. com/264606144) is helpful and should be watched as a supplement to this report if you are interested. You may want to download it and watch it step by step, as Glenn Venghaus proudly demonstrates how quickly you can work with the device. But in the end, training is essential, similar to learning to write blind.

Comment

Beatstep or its bigger brother, the APC40, are the perfect solution if you’ve upgraded your computer and don’t have enough money for the Blackmagic consoles, but still want to work smoothly without ruining your wrist with the mouse. The smaller controller is even useful for a laptop on the move. There is really only one catch: the whole thing is only available for Mac OS. There are said to be people who have a Hackintosh machine configured for this reason alone ..

The post It can also be cheap: Beatstep Resolve Edition first appeared on DIGITAL PRODUCTION and was written by David Feuerstein.

Houdini can read in external data in various ways. The most comprehensive is certainly a self-written Python parser, but that is not necessary here, because Houdini comes with the Table Import Node as standard. This makes it possible to import tables in CSV format. If you look under the bonnet of the table import node, you will of course find a Python script there anyway. This is one of the reasons why I like Houdini so much: almost everything is open and can be studied or adapted to your own needs.

Import

The CSV format contains values that are separated by commas (CSV = comma separated values). These can be words or numbers. Most spreadsheet programmes can save or export tables as CSV. I use Google Sheets here, and it works great: the table import node initially only creates points, which then contain these values in attributes. I use the attributes:

@word, @pscale, @font.

@word gets the values from column A, which is the first column. In Houdini, counting usually starts with zero, hence Column Number 0. The attribute type is a string.

@pscale is a special attribute specified by Houdini. @pscale stands for Point Scale, i.e. the size of a point. This is Column Number 1, and the type in this case is a float, i.e. a floating point number. I could therefore also have entered 1.5 or 2.3 as values in the table.

i have defined @font as type integer, i.e. as an integer. As I want to use three different fonts, I have entered 0, 1 or 2 as values in the table.

The Table Import can also translate (e.g. Lat/Long to Sphere), but the Translator is not needed here.

The second node is Enumerate. This creates an @index attribute with which the points are counted in order to be able to assign them later. The group type must be changed from “Primitives” to “Points”. The next two nodes are not absolutely necessary, but as I wanted to create other sizes and these should be somewhat random, I first used Attribute Expression to convert the @pscale values 1,2,3 into 1.5, 2 and 2.5. To do this, “Custom” must be entered in the node attribute and “pscale” as the name and “Float” for the type. I use the VEXpression for this: “1 self * .5”.
And of course, I could have entered these values in the table straight away, but I didn’t. The zero named here as “OUT_points_with_attributes” is not necessary for the function, but is part of good style.

Loop it!

Now the first loop comes into play. This is a For Each Point loop. It contains 3 font nodes, one for each font. Firstly, I created a font node for this and added the spare input required later. To do this, click on the cogwheel and select “Add Spare Input”.

This font node was then referenced twice using drag-and-drop with the Shift, Ctrl and Alt keys held down. For the copies, I then held down the Shift and Ctrl keys and clicked on Font to remove the reference link. Alternatively, this can also be done with the right mouse button menu and “Delete Channels”.

Fonts

The most important node when it comes to text is of course the font node. It can generate both polygons and Bezier curves or both at the same time. I use polygons here. I have set the level of detail to 4 so that the tessellation is nice and fine.

Working with Bezier curves is also great, but unfortunately not useful here, as the UV layout node used later cannot process them. Now it gets a little more magical or technical. In the “Spare Input0” parameter, the “../foreach_begin1” node is referenced by drag-and-drop or, if you want and like typing, you can do that too. The text to be created is normally simply entered in the text field, but we want to read it in from the CSV table, which has already been converted into points. Backticks can be used here to execute code.

The command required here is “points”, whereby it is not about several points, but about string values from points. The “s” at the end stands for “string”. The first spare input is addressed with “-1”. The zero after it is the first point, here it is always just one point anyway, as we are looping over the points. Then “word”, because we want to read the @word attribute. Brackets around it and a backtick and that’s it.

As an aside and for the sake of completeness, “Add Text Attributes” should also be mentioned here. It is not needed here, but is very cool for other text gimmicks. If the box is ticked, the attributes @textindex, which indicates the number of letters in the word, and @textsymbol, which indicates which letter it is, are created for each letter or primitive. However, this is an ASCII value, i.e. a number. “f”, for example, is then 102.

The three font nodes are then connected with a switch that reads the @font attribute. I have also created a spare input for this. This time it is the “point” command and not “points”, as only a number is read out here and not a string. So “point(-1,0, “font”,0)”. In this case, “-1” is again the spare input, “0” is the first point, “font” is the attribute and the last “0” is a necessary argument, which doesn’t really make sense here. However, if we wanted to read out a vector, “0” would be X, “1” would be Y and “2” would be Z. This is also only mentioned here for the sake of completeness.

Copy to points

Okay, Houdini! Now we come to the copy to points node. First of all, some information in passing: This node will change a lot in H18 and make actions like this easier. No matter. Pack and Instance is not needed here. Transform Using Point Orientation is also not required here, but can also be on. Copy Points Attributes is used because we still need @index. So enter “index” under Set/To Primitive. Delete everything else.

Now you should be able to see a bunch of fonts on top of each other. Before, there was nothing to see in the viewport except a dot in the centre, at most. Tip: In the “foreach_end1” node you can set to “Single Pass” for debugging, then only one iteration of the loop is executed. And always keep an eye on the geometry spreadsheet, where you can see the values of attributes.
Now we come to the UV layout node, which is used here to distribute the words in a shape. In the picture, I have coloured the shape green. I have left space for the two logos of DP and DIGITAL PRODUCTION. Connecting this shape to the second input of the UV layout node should not be too complex. Of course, the words with the @index attribute go into the first one.

UVs

The UV layout node normally uses the @island attribute to delimit the UV parts from each other and the @uv attribute for the positions of the vertices on the UV map. Since there are no UV coordinates here at all, we replace “uv” twice with “P”.

in Houdini, @P is the position of the vertices. For Axis Alignment we select “none” and for Island Rotation Step we set “No Rotations”. If you want to create a Word Cloud with rotated words, they should either be rotated beforehand or you should select 90°, for example, so that no words are upside down.

Padding is the distance between the shapes to be distributed, in this case words, and Scale should be set to “Largest Packable”. The “Advan…” settings are also interesting. This must stand for Advanced. There are iterations here. Here the node randomly tries different layouts and then uses the layout with the best space utilisation. However, each iteration takes time, and 4 is sufficient for this purpose. Different layout versions can be generated with “Random Seed”.
That’s it as far as the layout is concerned, but now we want it in 3D. To switch to a so-called Packed Workflow, we need an @name attribute with a string, i.e. text content. At the moment, we only have an @index attribute, and these are numbers. We do this with an attribute wrangle node.

Select “Primitives” under Run Over and enter the following VEXpression: “s@name = sprintf(“%d”, i@index);”. This creates an @name attribute, which then contains the number as a string. For more details on this VEX function, please refer to the Houdini documentation, which would go beyond the scope of this article.

Now the whole thing is packed, i.e. each word is now represented by a point. This is practical because it is now easier to select the words, for example, in order to make manual corrections to the positions. Simply use an Edit Node to do this.

Before or after the edit node, I used an attribute copy node to write the attributes from the beginning @font, @pscale, @word back to the points, which now contain the packed geometry. Again, @index is used to assign the source and target points (Attribute to Match). Only @pscale is actually needed, but never mind. If you want, you could customise this even more variably and select words more easily or, for example, extrude them differently depending on the font.
Now rotate another loop and extrude the words. To do this, create a For-Each Primtive Loop and place an Unpack followed by a Pack Node. A polyextrude is placed in between.

Then either drag and drop the “foreach_begin3” into the spare input created or enter “../foreach_begin3”. I have set the parameter “distance_multiplier” to 0.025.
The magic is in the Distance parameter; enter “point(-1,0, “pscale”,0)*ch(“distance_multiplier”)” enter. Now @pscale is used to control the thickness of the letters. Do not forget to tick the “Output Back” box, otherwise the letter will be open at the back.

Finally, a file node to save the geometry. It can then be integrated into the rendering scene. The outline plate behind the words was also created procedurally, unfortunately no longer part of this article. But this much can be revealed: I converted a geo into a volume, more precisely into an SDF/VDB. Then enlarged it as an SDF or made it thicker. Then “vdbsmooth” and converted it into a mesh. An Intersection Aanalysis followed by Polypath, then Resample, then Fit and Resample again, and the outline is ready.

Outlook

I would also have liked to have written something about splines, i.e. curve modelling and editing. This works very well in Houdini, even if it takes some getting used to. I would also have liked to discuss rounded edges. But I ran out of pages – we’ll just do that in one of the next issues.

The post Blergh! Word Art! In Houdini? first appeared on DIGITAL PRODUCTION and was written by Olaf Finkbeiner.

The VFX powerhouse Houdini from SideFX is part of the standard repertoire of renowned VFX houses. A symbolic toolbox that has the right nuts and bolts for the realisation of every effect. The only catch is that newcomers and newcomers in particular struggle with the steep learning curve at the beginning. A good deal of perseverance, discipline and the ability to think outside the box, coupled with knowledge of physics and maths, usually lead to great success in a reasonable amount of time.

Now there is a professional group in computer graphics that receives a kind of speed booster for switching to Houdini. We are talking about the (3D) modelling department. Alexey Vanzhula designed the Direct Modelling Toolkit and is constantly developing it further. This is a special toolbox that combines the best and most efficient features from a wide range of digital content creation within Houdini. There is also another major advantage: unlike other commercial plug-in solutions, the Direct Modelling Toolkit is quite affordable for freelancers. In the following, we will take a closer look at whether Vanzhula’s modelling wonder box makes Houdini suitable for modelling – from the point of view of classic modelling methods.

Obstacles when getting started or switching over

Houdini’s working method is procedural throughout. Every train of thought that leads to a solution is recorded with one or a series of nodes, and countless trains of thought flow into the completed solution paths for the realisation of impressive effects. The result is node graphs of considerable dimensions. Each adjustment to a node transfers the update through the entire node strand, and the result is visible in the viewport. In terms of the basic working method, this means that the workflow is predestined for procedural modelling and parametric modelling; in other words, the creation of objects – regardless of their size – based on sets of rules that can be permanently influenced and always present the current result.

Nodes that supply the set of rules with important parameters must be visible in the graph, as well as their parameters available to the user, which can usually be collected in a specially created menu. Shortcuts are not explicitly required, as programme code or code from a scripting language is usually used. The node structure or the structure of the node strings is important.

The situation is different with classic modelling. This requires the creativity and craftsmanship of a 3D artist. Just as a traditional artist mixes colours on a mixing board from different base tones and brushes the artwork onto the canvas with a variety of brushes, 3D artists have to refine their models bit by bit with a handful of tools. A node that represents a specific work step must therefore be executed several times in succession – similar to the undo list in modern DCC programmes – until the desired effect can be seen on the 3D model.

The logical node structures in procedural modelling are generally structured with a focus on specific functions. For classic modelling, this means that each symbolic brushstroke is represented with its own node in the worst case. If a 3D model now has more than one hundred steps to completion, one hundred nodes are linked one after the other in the graph, between which you have to navigate. Instead of concentrating on the actual work, the artist is busy navigating the node graph and adjusting parameters.

SideFX already took a big step towards 3D artists in Houdini version 16.5 with the so-called Game Development Toolset. This contains geometry tools designed to make work easier. However, the focus of the tools was clearly purely on the creation of game art, and the pure modelling aids were limited.

In addition to this, there is also a thoroughly gruelling fact for newcomers and newcomers: graphs in Houdini are by no means purely one-dimensional, even if the hurdle from OBJ to SOP level has been overcome. In fact, gigantic node networks can be accommodated in individual nodes. On the one hand to organise the building blocks according to logic and on the part of Houdini to define certain areas. For example, there is a level for geometry (OBJ level), the surface level (SOP level) starts directly below it and it is possible to jump even deeper into VOPs. Different areas have their very own contexts. A simplified representation can quickly become an obstacle in the area of modelling, at least when viewed from the perspective of classic modelling. No need to despair, thought Vanzhula, and set to work.

Direct modelling in the spotlight

The hard facts: The Direct Modeling Toolkit is available as a Houdini Digital Asset (HDA) and is compatible with the current daily builds of Houdini 17.5. Included in the Direct Modeling Toolkit is a selected collection of advanced tools specifically for modelling. Optionally, it is possible to open a small overlay menu in the active viewport at the touch of a button and quickly access the desired tool.

Libraries!

By default, the library already contains a number of objects that are optimised for subdivision surface modelling. The library can be ideally combined with the DM tool “Insert Mesh”. Areas on the source geometry can be selected to serve as an anchor for an object in the library. In short: objects from your own database are positioned at the desired locations and replace the source area in whole or in part in order to make refinements. An example of this is hard surface modelling, which is populated with additional geometry based on subdivision surface modelling principles in order to attach rivets and complex screws to metallic surfaces.

Soft booling

Another tool that harmonises very well with our own object database is called “Soft Boolean”. As the name suggests, it is an advanced tool based on Boolean operations. Advanced basically refers to the processing of the underlying data and the visual result. This can be the connecting lines, for example, to generate efficient quads and optimise the alignment of the associated normals for shading. Both tools also ensure that the UVs are optimally adjusted and that no overlapping or heavily distorted areas are visible.

Unwrap

It is pleasing to read that Vanzhula has also developed a very efficient UV unwrap tool in contrast to the native Houdini tools, based on the UV unwrap functions of 3D-Coat and or Headus UV Layout. 3D artists can use edge loops to mark out areas that are separately subjected to a planar unwrap. After each edge loop, two areas are defined and the respective vertices are grouped. Two UV clods are then created. The principle can be repeated or cancelled as often as required. Furthermore, the padding can be adjusted via a parameter; the optimum positioning after the creation of further UV clods takes place automatically.

As a special treat, it is not even necessary to open Houdini’s UV view screen. The DM tool displays the unfolded UV floes directly next to the actual geometry in the active viewport.

The Direct Modelling Toolkit comes with two shelves filled with tools. One contains all the tools that are often used, including the Boolean operations, all of which are stored with a self-explanatory icon design. The second shelf allows the 3D artist to customise the quick selection menu according to their own wishes. Vanzhula has also disclosed the Python code for such cases. As befits Houdini, all tools in Direct Modelling are equipped with a benevolent number of setting options to produce the best possible result.

The standard tools in the quick selection menu are also called DM Mesh Tools. You could also call them a symbolic Swiss army knife for modelling. They include tools for so-called flattening. A whole series of vertices can be optimally aligned to a desired axis – horizontally or vertically with the starting point. The selected vertices can also be centred horizontally or vertically at the touch of a button.
But that’s not all. There are certain work steps that require a great deal of sensitivity and may take a lot of time. One of these steps is the optimal alignment of edge loops in order to create smooth surfaces. Smooth in the sense of benevolently interpolated normals of the contiguous corners, so that no artefacts (hard edges or shadows) are visible where they should not be.

Vanzhula has developed the “Smooth Edges” tool for this case. Corners that appear hard and cast shadows can be selected. The next step is to activate the tool from the quick selection menu or via a shortcut, and the edge assumes an optimum position determined by the programme, which can be fine-tuned using the parameters provided if the automatic adjustment does not meet the visual requirements.

Mäxchen’s array

3ds Max is equipped with an array tool, which is now also available in Houdini in an improved form. Seasoned Houdini enthusiasts would certainly refer to the Copy Stamp SOP Node at this point, Vanzhula offers a ready-to-use tool for direct use.

Cloning takes place either in line form or as a grid and in circular form. There is great joy when several array functions are used in succession, as this allows you to create structures relatively quickly, which can also be used for modelling or positioning objects. In conjunction with the Boolean operations, it is possible to work efficiently, as is familiar from Modo in conjunction with the Mesh Fusion plug-in – only with Houdini’s procedurality.

In addition to the major innovations, there are also improved tools available in Houdini, such as the Bridge Tool, which allows more scope for intuitive customisation – even if the starting point is selected components.

Another procedure in Houdini that does not always seem trivial for newcomers and those switching to Houdini is the creation and assignment of materials. There is a separate DM tool with the simple name “Material” for this case too. Instead of setting up an SOP network and material builder nodes by hand and assigning the respective materials at SOP level to the respective objects or vertex groups via material SOP nodes, it is sufficient to use the “Material” tool
Vertex groups, it is sufficient to select the desired geometry and select the DM Material Node. The steps mentioned above are then carried out automatically.

DM Mesh Tools

A point that has not yet been mentioned in the DM Mesh Tools: There is virtually a mesh building mode, where the 3D artist creates an object with the DM Tools, and after a successful completion, the entire building process can be finalised. To do this, the DM Bake
Function is selected. In Softimage XSI, the process was called “Freeze Operator Stack” and “Freeze Modelling Relations”. This reduces the number of nodes to an absolute minimum and, in the best case scenario, all work steps are merged into one node. If different materials have been assigned, material SOP nodes are available. Of course, the 3D artist can decide what to do with the entire construction process. In addition to deletion, the OBJ node can also be retained alongside the
Creation of the result – Baked Result.

Important helpers and summary

There are other important helpers among the DM tools. For example, an all-encompassing deformation tool. Like the Deform Modifier in 3ds Max, but on steroids in terms of functionality. Bend, Taper, Twist and Quish are combined in one tool, along with an adjustable range of effects. They allow for a quick application of irregularities. If the underlying geometry does not have the polygonal structure required for unshaping, another DM tool can help. We are talking about component-sensitive connect and weld functions. For 3D artists, this means that no unwanted results can be seen during the connect or weld process that have to be corrected afterwards in a time-consuming process.

If a high-resolution geometry is available as a basis to which adjustments are to be made, then there is the option of using the DM Separate tool. As the name suggests, a selected part of the main geometry is separated and the completed object is restored after successful editing.

Tweak

Another exciting DM tool is called Tweak and is similar in functionality to the ZBrush Move tool. In short, it is a kind of sculpting brush with the option of moving, inflating or smoothing geometry. Either locally or in symmetry with a previously selected axis. It is also possible to set a kind of fading or strength of the effect using a slider, which offers the 3D artist more flexibility for fine-tuning. It’s almost a further development of Houdini’s native Edit SOP Node, as the tool is not limited to selected components, but includes the components that lie within the adjustable radius of effect of the mouse pointer.

Costs and reference

The previously described helpers for getting started and switching are, of course, selected features that were very much focussed on in the test trials. The entire repertoire includes many more helpful tools that, in principle, no Houdini user should be without. Therefore, every Houdini user should take a look at the tools, and if you haven’t already created your own tools and want to save time, then the DM tools are a good investment. If only because Vanzhula is constantly developing the tools further, according to his comments on social networks.
However, Vanzhula did not develop the tools out of good humour and fun alone, which is why he charges a small but substantial fee of 100 US dollars before tax. A price that is quite reasonable for the service and really helps. Not only for beginners and newcomers, but also for experienced users who want to focus more on modelling and avoid redundant work steps in addition to pure FX work.

The post Direct modelling: modelling without obstacles first appeared on DIGITAL PRODUCTION and was written by Rainer Duda.