Karma Renderer FAQs


What is the main difference between Karma and Mantra?

Mantra renders from Houdini using the ifd format and is not available as part of the Solaris LOP context.

Karma renders using the USD format and can only be utilized from within the Solaris LOP context.

Learn more here about the differences between the two render engines.

Is Karma ready for production use?

With H20, Karma CPU is production ready. The new engine Karma XPU has moved from beta to gold.

If you are using Solaris for lighting, you may want to consider using Karma XPU for interactive rendering in the viewport and Karma CPU for final rendering.

Learn more here about the differences between the two engines.

How does Karma CPU and XPU in H19.5 compare to Mantra?
Feature Mantra H19.5 Karma CPU H19.5 Karma XPU
Status Production-ready Production-ready Beta
       
CPU Renderer Yes Yes Yes [Hybrid]
GPU Renderer No No Yes [Nvidia]
       
USD/Solaris Support No Yes Yes
IFD Support Yes No No
Open Image IO Yes | with Env Variable Yes Yes
       
Standard Surface Shader Principled - VEX Principled - VEX/USD Preview/MaterialX USD Preview/MaterialX
VEX shading Yes Some trace() function support No
       
CVEX: Lens Shader Yes Yes Karma Physical Lens
CVEX: Volume Procedurals Yes Planned for Future Release No
       
Toon Shader VEX Shading VEX Shading No
Rounded edge/Dirt masks Yes Yes No
Texture Baking Yes Preliminary Support No
       
MaterialX Surface Shaders No Mtlx Standard Surface/USD Preview Mtlx Standard Surface/USD Preview
MaterialX Disney 2012/2015 No No No
Custom MaterialX PBR Shaders No Yes Planned for Future Release
MaterialX SSS No Yes Yes
MaterialX Color Management No Planned for Future Release Planned for Future Release
MaterialX Displacement No Yes Yes
       
Material Overrides Material Stylesheets [USD] | Assign Material and Material Variation LOPS [USD] | Assign Material and Material Variation LOPS
       
Adaptive Sampling Yes Yes No
Motion Blur Yes Yes Yes
Depth of Field Yes Yes Yes
Physical Sub Surface Scattering Yes Yes No
Random Walk Sub Surface Scattering No Yes Yes
Volumes Yes Yes Yes [Pyro Preview Shader]
Heightfields Yes Yes via Solaris Yes via Solaris
Instancing Yes Yes Yes
Nested Instancing  No Yes Yes [Fixed Number of Levels]
Deferred Geometry Load Yes Planned for Future Release Planned for Future Release
Subdivision HoudiniSubdiv/OpenSubdiv OpenSubdiv OpenSubdiv
Displacement Shading Yes Yes Yes
Crowd Support Yes Partial Support | USDSkel support, but not optimized Partial Support | USDSkel support, but not optimized
NURBS Yes Tesselated at Fixed Rate Tesselated at Fixed Rate
Lens Shaders Yes Custom VEX lens shaders Karma Physical Lens
Absorption and Nested Dielectrics Yes Nested Dielectrics No
Pyro Shader for Volumes Yes Yes SimplifiedLimited Version
HdCoordSystem support for shaders No Yes No
Uniform Volume Geometry Yes Yes No
       
Denoising Optix | Intel Optix | Intel Optix | Intel
AOVs Yes Yes Yes [no LPE])
Deep Images Yes Yes No
Cryptomatte Yes Yes No
       
Light type: Point Point Light Yes Yes
Light type: Dome Environment Light Yes Yes
Portals on Dome Light Portal Light Yes Planned for Future Release
Light type: Distant Distant Light Yes Yes
Light type: Disk Area Light Yes Yes
Light type: Rectangle Area Light Yes Yes
Light type: Sphere Area Light Yes Yes
Light type: Cylinder Area Light Yes Yes
Light type: Geometry Geometry/Volume Light Yes (points, curves, meshes, volumes) Planned for Future Release
Light type: Portal Yes Yes No
       
Shaping Control: Cone Spot light Yes Yes
Shaping Control: Focus Yes Yes Yes
Shaping Control: Barn Doors Yes Yes Yes
Shaping Control: IES Mapping Yes Yes Planned for Future Release
       
Light Filters No Yes Yes [Fixed Set]
Light Linking Yes Yes [No Geometry Lights] Yes [No Geometry Lights]
Geometry Lights Yes Yes [points, curves, meshes, volumes] No
       
Hair & Fur Yes Yes Yes
Render Curves Yes Yes [tubes, ribbons, oriented ribbons] Yes [tubes]
Render Points Yes Yes Yes
       
Viewport Render Yes Yes Yes
Render View Yes Solaris Viewport/Render Gallery Solaris Viewport/Render Gallery
Interactive Mplay Yes Yes Yes [No click to render]
Render Snapshot Gallery Yes Yes Yes
Render to Disk Yes Yes Yes
HQueue - Distributed Rendering Yes Yes Yes
Standalone Command-line render Yes Yes via Husk Yes via Husk
CheckPointing Yes Yes via Husk No
     
VEX FUNCTIONS      
- gather loops Yes Simple Trace (no shading) No
- illuminance loops Yes Never will be supported No
- trace Yes Simple trace function (no shading) No
     
Path Guiding No Yes No
Frustrum VBDs No Yes Yes
Light Shaping Yes Yes Yes
Per Instance Property Overrides Yes Yes No
How much longer will Mantra be supported?

Development on Mantra is limited to critical bug fixes. The plan is for this level of support to continue until the end of 2024 (two years after Karma XPU is released) at which time Karma will take over as Houdini’s only supported built-in renderer. For as long as they are on AUP, customers will be able to keep their unsupported existing licenses until at least 2025.

How does KarmaXPU and CPU in H20.5 compare to Mantra?

Karma XPU is production-ready as it reaches feature parity with Karma CPU in key areas and integrates well with the Solaris lookdev and lighting environment.

Go to the link below to compare the features found in Karma XPU, Karma CPU and the legacy Mantra renderer. Be sure to note that all development going forward will be for Karma.

GO TO COMPARE CHART >>