New Sparse Simulation Technology and Rendering

Nicholas Seavert

Posted on April 17, 2025

On Target

227

Simulate only in active regions where there is present voxel data. The active region is implicitly controlled by where there’s visible stuff (e.g. smoke), or through a explicit use-controllable activity map to combine with a pre-defined region.

Currently limited to a huge 8192x8192x8192 virtual simulation space for technical and performance reasons, meaning anything that fits within a 8192x8192x8192 bounding box is supported. Further lifting this restriction is planned for post-2.0.

EmberGen 2.0 combines both more efficient memory utilization techniques and sparsity to effectively simulate roughly 10-15x more voxels when directly compared to EmberGen 1.x, how much depends primarily on the sparsity of the simulation setup, with the possibility of even greater improvements. Roughly speaking you can take the bounding box of an EmberGen 1.x setup and multiply the voxels on each axis by 2-2.5x and get the equivalent level of detail in a similar setup in EmberGen 2.0.

• A 6 GiB GPU can simulate up to 200 million active (sparse) voxels, which is roughly equivalent to 1 billion (dense) voxels in EmberGen 1.0
• A 8 GiB GPU can simulate up to 300 million active voxels, which is roughly equivalent to 1.5 billion voxels in EmberGen 1.0
• A 16 GiB GPU can simulate up to 600 million active voxels, which is roughly equivalent to 3 billion voxels in EmberGen 1.0
• A 24 GiB GPU can simulate up to 1 billion active voxels, which is roughly equivalent to 5 billion voxels in EmberGen 1.0
• A 32 GiB GPU can simulate up to 1.5 billion active voxels, which is roughly equivalent to 7.5 billion voxels in EmberGen 1.0
• A 48 GiB GPU can simulate up to 2 billion active voxels, which is roughly equivalent to 10 billion voxels in EmberGen 1.0

The maximum number of active voxels by design is 2,147,450,880, which requires roughly 48 GiB of VRAM alone too store and operate.

All numbers above are without any kind of upscaling (higher resolution for certain components, e.g. 2x smoke resolution for 1x velocity resolution). It will be possible to simulate over 8 billion active upscaled voxels, which will be able to use more than 48 GiB of VRAM. This is roughly equivalent to 40 billion upscaled voxels in EmberGen 1.x.

It is also possible to trade VRAM efficiency for performance efficiency in certain ways if you don't need to simulate as many voxels as your GPU supports.

All of this comes with a newly optimized renderer for sparse volume representations.

New GPU Particle System

Nicholas Seavert

Posted on April 17, 2025

On Target

169

Particles in EmberGen 1.x are performance heavy and a bit convoluted. This rewrite will serve as a new foundation for future GPU particle emitter improvements. Over 500 million GPU particles supported on a 24 GB card. Better collisions, easier controls, and a lot more boom.

Volume Caching for Scrubbable Simulations

Nicholas Seavert

Posted on April 17, 2025

On Target

127

Since the beginning of EmberGen's life, customers have asked for caching simulations so that you can scrub through them. Ask no longer, because it's coming in 2.0!

Improved Mesh Rendering

Nicholas Seavert

Posted on April 17, 2025

On Target

57

EmberGen 1.x mesh rendering is a crude volumetric approximation of the imported meshes. EmberGen 2.0 will allow for properly shadowed and shaded polygonal meshes.

New Combustion Model

Nicholas Seavert

Posted on April 17, 2025

On Target

114

Combustion in EmberGen 1.0 is convoluted and difficult to get right with a wide array of difficult to understand parameters. In EmberGen 2.0, you have full control over how fast, big, and bad ass your combustion simulation is. Streamlined and easy to understand, more realistic combustion has never been easier.

MacOS Support on M-Series Chipsets

Nicholas Seavert

Posted on April 17, 2025

On Target

157

You've asked for years, and we are delivering. EmberGen will run on compatible M-series MacOS devices.

Import VDB Files

Nicholas Seavert

Posted on April 17, 2025

Completed

74

Import static and animated VDB files. The data is usable by the simulation to resume the cached simulation state, even if it is from another tool.

Inject: Fuel, Fire, Smoke, Temperature, and Velocity

Spline Shapes & Forces

Nicholas Seavert

Posted on April 17, 2025

On Target

83

Long asked for, finally delivered.. create custom shapes and force fields with the new spline tool in EmberGen. Export splines as JSON.

Selectable Viewport Items

Nicholas Seavert

Posted on April 17, 2025

On Target

58

In the viewports of all products, shapes, emitters, colliders, and more generally aren't selectable, but we are working on changing that. All items will be selectable with new gizmo graphics and shaders to go along with this new feature.

Curve controls for more parameters

Nicholas Seavert

Posted on April 17, 2025

On Target

46

The curve UI Widget is relatively new to EmberGen 1.x and was a by product of GeoGen development. There are a lot of parameters in EmberGen that could benefit from being remapped via in-node curves and we plan to investigate more use cases for these curves during and after the development of EmberGen 2.0.

HDRI Support for Skyboxes

Nicholas Seavert

Posted on April 17, 2025

Completed

67

Fully dynamic indirect lighting will be supported by sampling from an environment map, typically a HDRI or a simulated atmosphere.

We will support an adaptive refinement scheme, where the result is coarse (but good!) during preview and while simulating heavy scenes, and it will progressively improve itself as the simulation is paused, or during exports.

The technique used effectively gives you correct ambient occlusion (effectively average visibility) for free. The performance is generally quite good, and will always be turned on.

Supports rotating the environment map as well for fine tuning of your lighting.

Mesh Based Particles - Debris & Mesh Instancing

Nicholas Seavert

Posted on April 17, 2025

On Target

65

Sometimes you want to be able to instance meshes onto particles inside of EmberGen for debris simulations and this enables that behavior.

Animated 3D/4D Volume Textures for Games

Nicholas Seavert

Posted on April 17, 2025

On Target

42

4D Volume slice exports for games

Variable Component Injection - Custom Voxel Data (Multi-sim)

Nicholas Seavert

Posted on April 17, 2025

On Target

40

With EmberGen 1.0 there are a lot of limitations as to what information voxels can store and hold on to.

With variable component injection you will be able to store different values for fuel types, smoke color, and more to allow for multiple unique simulations and voxel types within your scene. A great use case to think of is if you have a bomb that explodes in the dirt, you would have a mix of white smoke from the bomb and brown smoke from the dirt. You may also have a scene where there are two types of fuel present that give off varying colors of both fire and smoke.

Emission from textures

Nicholas Seavert

Posted on April 17, 2025

On Target

68

We used to have it, then we didn't, now we do.. :)

Retiming Simulations & True Scene FPS Options

Nicholas Seavert

Posted on April 17, 2025

On Target

108

Users need the ability to retime simulations to match the desired frame rate, or have variable frame rates to support transitions to super slow motion, etc. Depending on your project you may need unique frame rates outside of EmberGen's default 60 frames per second. Easily switch your scene to run at 24, 25, 30, or even 23.97 frames per second if you're weird.

USD Format Support

Nicholas Seavert

Posted on April 17, 2025

On Target

59

Import and export support for USD (Universal Scene Description) files.

Wedging & Batch Processing UI

Nicholas Seavert

Posted on April 17, 2025

On Target

19

You can already export infinite variations within EmberGen within the file menu tab. We will add further UI enhancements to make variation exports more accessible.

Scriptable API

Nicholas Seavert

Posted on April 17, 2025

On Target

42

Use a scripting language of your choice to interface with, and automate our products.

1.2.4 Changelog

Nicholas Seavert

Posted on July 2, 2025

Completed

3

Fixed some artifacts on some GPUs in six point lighting render passes Fixed straight alpha particle rendering

Six Point Lighting & Normals Fixes

Nicholas Seavert

Posted on April 22, 2025

Completed

49

• Fixes an issue where there were undesirable rendering artifacts (lines) due to bad mips.
• Fixes an issue where our six point lighting shader mapping for Top, Left Right, was actually incorrect.
• Adds six point lighting settings back to the render tab so that you can adjust values for each light.
• Fixes an issue where "Six points black background" parameter was affecting the six points normal pass, even though that parameter does not show up when that pass is selected. We have changed the normal pass to work as if that parameter is off regardless of its actual state.
• Fixes an issue where 6 point normals & lighting would break looping flipbooks.

Alembic Particle Exports Investigation

Nicholas Seavert

Posted on April 28, 2025

Completed

27

We're currently looking into general widespread issues with our EmberGen particle exports such as:

• inconsistent id values due to us recycling particles for perf reasons
• no usable age attribute due to inconsistent ID's
• no animated color attribute
• nan positions
• other various problems.

We're also adding the ability set custom attribute names per export channel for particles like we do for VDB exports. For instance, your external DCC may require a velocity attribute called .vel when we export .velocity and as such you will be able to easily rename this.

The risk here is that the inconsistent ID issue may not be fixable due to how we originally coded the particle system and if that's the case then it will only be fixed in EmberGen 2.0 and not a 1.x patch.

1.2.3 Changelog

Nicholas Seavert

Posted on May 27, 2025

Completed

6

EmberGen 1.2.3

• Removed legacy "Particle max limit" parameter in the simulation node
• Fixed an issue with skybox rendering in "Shapes Scattering" and "Shapes Shadow"
• Added custom nested property/attribute names when exporting Alembic Particles
• Improved stability of alembic exports via semi-unique particle IDs
• Removed the upper cap of particles injections of smoke, flames, temperature and velocity
• Added step-back-once (Shift+Z) to timeline, allowing stepping back only the timeline without affecting simulation, ideal for timeline and imported animation workflows
• Added transform pin to particle export node, fixing coordinate system transforms for specific export options
• Added search to dropdown menus
• Changed reset shortcut to reset export preview playhead
• Enhanced variation export system to check for $(variation) variable in export nodes, disabling variation export with a message if absent
• Fixed an issue where there were undesirable rendering artifacts (lines) due to bad mips
• Fixed an issue where our six point lighting shader mapping for Top, Left Right, was actually incorrect
• Added six point lighting settings back to the render tab so that you can adjust values for each light
• Fixed an issue where the "Six point black background" parameter was affecting the six point normal pass, even though that parameter does not show up when that pass is selected
  • The normal pass now works as if that parameter is off regardless of its actual state
• Fixed an issue where the "Static Blend" blending mode would break looping flipbooks