The pitch: stop keyframing the math

Physics-style motion looks simple right up until you try to animate it by hand. You want an object to arc, spin, fall, and land with a believable rhythm. Then you end up nudging curves, correcting timing, and trying to keep the rotation from looking like it came from a different universe than the translation.

NodeMonkey built Inertia around the idea that artists should steer intent, not equations. The tool targets Blender 5.1 and is a Geometry Nodes-powered add-on that handles the math and generates trajectories, rotations, and gravity-based motion. The claim is workflow first: fewer clicks, fewer editors, and less time spent hand-authoring the same ballistic arc for the hundredth time.

A free version is available, alongside a paid edition. Pricing is shown as €0+ so you can name your own price, and pay what you think is fair.

Three systems, three kinds of pain relief

The core of Inertia is three built-in systems, each aimed at a familiar animation task that tends to spiral into curve surgery.

Projectile Inertia focuses on launched objects. The tool includes an auto-aim function intended to help consistently hit targets. Think arrows, thrown props, or anything that needs to land where art direction says it must land, while still pretending physics had a say.

Orbital Inertia targets celestial mechanics. If you ever tried to keyframe orbital paths and keep speed and curvature consistent, you already know why a dedicated system exists for it.

Curve Inertia keeps objects locked to paths with gravity-like behavior. The examples called out include jet fighters and roller coasters, which is another way of saying motion that must follow a path but still feel like weight and momentum exist.

All three systems sit inside Blender 5.1 and lean on Geometry Nodes rather than external solvers or custom simulation frameworks. About a third of the way in, here is the small gotcha you should keep in mind: any tool that generates motion procedurally can hide complexity behind friendly UI. That is great until you need to debug. Test early, test with your real scene scale, and test with the constraints you actually ship, not the demo that came in the download.

Viewport prediction: the part you will actually use

The most practical feature is a real-time predictive curve drawn directly in the viewport. The idea is simple: see the path before you press Play. That means you can adjust aim and motion direction with visual feedback instead of running the timeline like a slot machine.

The same preview concept applies to both projectile arcs and orbital paths, displayed as a live line in the viewport. It is a small change that can save a lot of micro-iterations, especially when you work under direction that changes its mind three times before lunch.

The Sources also claim you do not need to know Geometry Nodes to use the tool. Instead, you adjust sliders for Gravity, Friction, and Speed without opening the node editor. That is the classic adoption strategy for node-based power features: give artists a clean control surface first, let the curious dig deeper later.

Practical notes for production brains

If you plan to use Inertia for shots, treat it like any new procedural motion system. Run a few stress tests with your real frame ranges and scene scale. Check whether the motion remains stable when you change FPS, time-warp, or hand off to another artist who needs to tweak the result without breaking the rig. Verify how the generated motion behaves when you render on the farm or upgrade Blender mid-project.

https://nodemonkey.gumroad.com/l/inertia

The post Inertia brings clicky physics to Blender first appeared on DIGITAL PRODUCTION and was written by Bela Beier.

The animation-tool makers at Cosmo Mídias have released a new add-on for Blender called 3D Onion Skinning. According to the official documentation and the product page, it adds a simple but powerful way to visualise animation timing directly in the 3D viewport.

3D Onion Skinning uses Blender’s Python API and Geometry Nodes to create translucent “ghost” frames around the current frame in an animation. This lets animators preview frames before and after the current moment in the viewport, allowing them to analyse timing, spacing and motion arcs without switching between editors.

Key features

The add-on can display relative frames both before and after the current frame, with independent control over how many frames are visible and what colour each ghosted frame should use. It includes an auto-update system that refreshes the ghosted frames whenever the user scrubs the timeline or adjusts keyframes and graph handles, so the preview remains accurate during animation.

It supports multiple object types including meshes, curves, surfaces, fonts, metaballs and instanced collections. The developers also note compatibility with library overrides and linked data. Visualisation works in both solid view and render view. In render view, the ghost frames automatically fade based on their distance from the current frame, improving clarity when previewing dense motion.

The interface is compact and minimal. A shortcut (Ctrl + Shift + Alt + O by default) opens or hides the add-on panel. Each parameter has a tooltip to explain its effect, keeping the design consistent with Blender’s native UI conventions.

Compatibility and implementation

The developers state that 3D Onion Skinning works natively with Blender 4.5 LTS and newer. The add-on does not require any external dependencies beyond Blender itself. It generates baked cache files on disk to store ghosted frame data. The (Quite cool and interactive) documentation recommends saving these caches to a local SSD path rather than a cloud-synchronised folder such as Dropbox or Google Drive, as doing so could cause update issues.

Use-cases

Cosmo Mídias presents the add-on as useful for a wide range of animation tasks. It helps students and educators learn timing and spacing, supports character animators refining pose-to-pose transitions, and aids motion-graphics artists working on complex movement. It can also help game-animation teams fine-tune short gameplay loops directly in the viewport without exporting repeatedly.

Pricing and availability

The 3D Onion Skinning add-on is available for purchase at a price of 9.90 USD from the Superhive marketplace, formerly known as Blender Market.

Why this matters

Checking timing and spacing in 3D animation often requires switching between frame playback, dopesheets or graph editors. Traditional onion-skin tools are typically 2D overlays, which lose depth and spatial accuracy. 3D Onion Skinning moves that preview into the 3D viewport, allowing animators to observe geometry movement directly in space relative to the current frame.

For production, this tool could reduce iteration time when refining animation or motion-graphics sequences. The ability to display motion trails and ghosted frames together can help animators and supervisors communicate adjustments more clearly during reviews.

Final thoughts

3D Onion Skinning focuses on a single function: frame ghosting in three-dimensional space and implements it using Blender’s native tools. This simplicity means low maintenance, no extra dependencies and minimal setup time. However, as with all new tools, artists should test it in their own pipelines, particularly when working with linked assets or large scenes, before integrating it into production.

The post New add-on for Blender brings onion skinning layering into full 3D first appeared on DIGITAL PRODUCTION and was written by Bela Beier.