Archive republication: This technical review originally appeared in Digital Production 05:2018 and was republished online in August 2021. Renderer behaviour, compatibility, performance and workflow details reflect the historical software version.
This article originally appeared in DP 05 : 2018.
3ds Max, Cinema 4D, Blender, Maya and many more. – All common 3D tools come with very good render engines as standard. But very good is often not enough and the consistency of the renderers provided is not always guaranteed – especially with 3ds Max. For example, Mental Ray was replaced by Arnold in version 2O18. The licensing policy of some providers has also changed, meaning that free use for network rendering of the render engines supplied is no longer guaranteed and an occasional look at the alternatives makes sense.
Over the years, a wide range of different players have established themselves in the field of render engines, some of which are better, some worse and some more expensive than the in-house tools. In the last DP, a number of current alternatives have already been presented.
Competition is known to stimulate business and external pressure ensures that there is no resting on the manufacturer’s laurels.
The open source sector in particular is stepping on the gas. It is therefore not surprising that AMD is providing another tool for fast, photorealistic rendering in the form of Radeon ProRender – free of charge!
Radeon ProRender is AMD’s photorealistic render engine. ProRender is based on OpenCL and utilises both CPU and GPU with a strong focus on AMD’s Radeon graphics cards.
OpenCL (Open Computing Language), not to be confused with OpenGL (Open Graphics Library), is a development environment with a special focus on the parallelisation of processes on various hardware components.
ProRender was presented by AMD for the first time at Siggraph 2016. Based on the original FireRender SDK, Radeon ProRender, in combination with the Radeon graphics cards, was intended to provide an answer to Nvidia’s dominant role in the high-end graphics sector. However, ProRender is not only intended to be used on AMD graphics cards, but also on alternative graphics cards. ProRender is now also a component of Maxon’s Cinema 4D, and plug-ins for the open source renderer are now available for a number of other 3D tools. We took a closer look at the plug-in for 3ds Max. The focus here was on a first impression.
Technology, GI, Render Engine
Radeon ProRender is a renderer based on biased rendering and path tracing. As a reminder: Biased rendering – the light distribution in a scene is determined in a simplified lighting model. The methods used are approximations of a real light distribution and are used to optimise speed. Examples are light caching or irradiance maps. The focus is on performance. Well-known renderers are Mental Ray or V-Ray.
Path tracing – unbiased method for calculating the final result using light tracing from the camera. When ProRender is started for the first time, the hardware is scanned – if no OpenCL-capable graphics card approved by AMD is available, ProRender recognises this and adjusts the hardware configuration accordingly.
Progressive rendering is used to calculate the scenes. Similar to Iray or V-Ray, the calculation is performed by refining the image quality with each pass (render pass). The number of render passes to be calculated can be set manually. Alternatively, the calculation time to be used per image can be specified.
Interface and operation
The installation complies with the usual standards and once set up, Radeon ProRender is available in the Render Setup (F10). The first calculation initiates the shader cache and can take several minutes depending on the hardware used. All subsequent image calculations are much quicker.
The preset render settings are sufficient for a first impression and a reasonable result. Depending on the type of scene, we recommend reducing the render passes for initial test runs. ProRender uses 3ds Max’s own video frame buffer and provides its own very extensive material library. As with all physical renderers, it is advisable to ensure that the system units are correct, as the physical units contribute significantly to the correct calculation of the light distribution.
What is pleasing at first glance is the clarity of the possible settings. Simple handling and fast results are clearly the main focus of ProRender.
If you have any questions about settings and parameters, the supplied help file is useful. This is included in the form of a .pdf document and is equipped with sufficient image material and screenshots of the render menu and ProRender materials and maps examples. As with many other additional helpers for 3ds Max, the help is only available in English. In addition, there are some tutorials online that make it easy to get started with ProRender.
Workfow – Migration
Radeon ProRender works seamlessly with the standard materials and photometric light sources of 3ds Max. ProRender does not particularly like mental ray materials or materials from other render engines and indicates the use of its own maps for displacement, for example, when rendering. There is no script for the automatic conversion of larger scenes, as is the case with V-Ray or Corona, for example.
Materials and maps
ProRender provides an extensive selection of its own materials, which are sufficient for almost all requirements. In addition to the actual materials, an extensive material library is also installed, which contains a range of interesting materials from glass to paper.
The ProRender materials are
i RPR Blend – ProRender blend material i RPR Diffuse – corresponds most closely to the standard 3ds Max material
i RPR Diffuse Refraction – material with additional refraction properties
i RPR Material – combination material for surfaces, volumes and displacement
i RPR Microfacet – material for metals and reflective surfaces
i RPR Microfacet Refraction – material for metals and reflective surfaces with refraction
i RPR Open Nayar – material for rough and natural surfaces
i RPR Reflection – material used exclusively for reflections – in combination with NPR Blend
i RPR Refraction – Material used exclusively for surfaces with refractive properties
i RPR Transparent – Material used exclusively for transparent materials in combination with RPR Blend
i RPR Uber – Mega material for the use of various shaders such as
i RPR Volume – material for lantern light, fog and haze
i RPR Ward – material for plastic and dull metals (e.g. anodised or coated surfaces)
In addition to the maps that can be used in 3ds Max, ProRender offers an additional list of custom map types. Some of these extend the existing 3ds Max maps. An overview and description can be found on the website. After selecting ProRender in the render setup, the preview of the materials is automatically calculated with ProRender so that the visualisation corresponds to the material used in the scene.
Interactive Rendering
The interactive rendering option Active Shade integrated in 3ds Max is fully supported by ProRender in the Material Editor with preview materials created by ProRender (example test scene “Dragon” AMD) and delivers reasonable, if not overly performant results.
Cameras
ProRender uses 3ds Max’s own physical camera and its settings for e.g. DOF or FOV. The standard camera may generate incorrect results when using ProRender, so the use of the physical camera is always preferable.
Light sources
ProRender works smoothly with the photometric light sources and offers support for HDRI maps via IBL (Image Based Lighting) in the environment settings of the render setup.
A dedicated daylight system can also be activated here, which offers basic settings for the georeferenced location and time of day, similar to 3ds Max’s own daylight. It is also much easier to search for a location here than in the 3ds Max options.
Render Elements
ProRender supports the option of rendering scene elements separately for post-processing and provides a selection of custom render elements under the render element settings.
Price
AMD provides Radeon ProRender free of charge.
Conclusion
AMD has launched an interesting addition to existing render engines. Radeon ProRender may be optimised for AMD graphics cards, but it also delivers convincing results on Nvidia cards or when rendering purely via the CPU, and the quality is impressive. The operation of ProRender is uncomplicated and makes no special demands. Fine-tuning is easy with the included help and the tutorials available on the web. Using the in-house standard materials from 3ds Max, initial results are achieved without any problems. Using the ProRender materials speeds up the rendering process. If you want to test files with MR materials or materials from other providers, there is no way around manual conversion in the Material Editor. Freely available material converters such as the converter from Motiva(www.motivacg.com/material-converter) can be helpful – at least for converting to standard materials.
The example provided by AMD has just under 1.6 million polygons and four photometric light sources and was calculated with 50 render passes on the test computer in four minutes. Interactive rendering using Active Shade is sufficient, but it feels like it takes far too long. The ProRender can be used in a network without difficulty using Backburner.
ProRender has a lot to offer and delivers fast, uncomplicated and high-quality results. If you neglect the search for toon shaders, your own video frame buffers and more detailed parameters, you can give ProRender a chance without hesitation. If you have time and enjoy testing, you should take a look at this interesting renderer. Anyone already using a renderer such as V-Ray, Octane or Corona will probably not seriously consider ProRender as an alternative. However, considering the fact that ProRender is available free of charge and is now an integral part of the current version of Cinema 4D, it is definitely worth keeping an eye on this renderer. First impression: The renderer is appealing and offers a lot of possibilities – free of charge. ProRender is just starting out and clearly whets the appetite for more. We’ll keep an eye on it.
