Limitations & Known Issues

On this page you will find known issues and limitations that the development team is aware of, along with workarounds where applicable.



Interior mode

Interior Mode does not support material samples.


Caustics have a different appearance in the Real-Time View and rendered output.

 Details and possible solution

The Real-Time View uses a slightly different approach from the Output window when rendering, this is especially apparent when dealing with caustics with Interior Mode.

Possible solution: Try to increase the amount of samples.

Volumetric Caustics are only supported in Interior Mode.

Volumetric Caustics are not rendered when Light Sources are contained inside a Scattering Medium volume.

Volumetric Caustics are not supported in GPU mode.

Render Passes

Passes with Interior Mode are missing Specular Reflections of Light Source materials.

Depth Pass has artifacts when rendering is stopped before finishing with Interior Mode.

Opacity textures are not supported by Refraction render pass in Interior Mode.

Bump textures are not supported by Render passes in Product Mode.

Caustics cast onto the ground material will not Show up in the caustics pass.

GPU Mode

Following materials/textures/geometry types are not supported in GPU mode:

  • Cutaway material: objects with this material will be ignored.
  • NURBS: NURBS-only objects will be ignored in GPU mode. Objects that have both triangles and NURBS data, will be shown as triangles.
  • Legacy textures,from KeyShot 6 or earlier, (except Texture maps) are not supported. They will be ignored in GPU mode.
  • Curve geometry: GPU mode has limited support for Curve geometry, e.g. imported from Alembic, Max, C4D or Maya. Curve geometry that is not fully supported will either be ignored or appear wrong.
  • ZSpheres: GPU Mode does not support zsphere geometry (transferred from ZBrush).

If you run into one of these, a warning icon  will appear in the top right corner of the Real-time View. Click the icon to get info about what parts of the scene are impacted and by what.

Materials and Textures



Opacity maps on cutaway caps are not supported

Fade Animations are not supported with cutaway materials 

Co-planar surfaces may produce artifacts with inherit/material caps

If you have two co-planar parts where one is excluded form the cutaway and you use inherit caps or material caps. Artefacts can occur on the surface of the excluded material.

Cutaway material may interfere with shadows on the environment ground

 Details and workaround

If the cutaway object touches the environment ground it will cut that just as it cuts into regular parts.

Workaround: Add a groundplane (Edit > Add Geometry > Add Ground Plane) and exclude it from the cutaway.

When the Camera is inside the cutaway object, Color caps and Material caps are not working as intended


When using material caps or color caps and the camera is positioned inside the the cutaway object, all objects in the scene will be displayed with the cap material/color.

Excluded objects in cutaway have incorrect reflections

Objects excluded by cutaway show reflections of the inside of the object being cut.

Bad shadows on excluded cutaway objects

The shadows on excluded objects appear as if the cut objects are still visible.

Fade Animation is not supported when viewing through a Cutaway object.

Scattering Media and Cutaway materials in the same scene will sometimes lead to undesirable results.

  • If there is overlap between the cutaway and the Scattering Medium, and the Scattering Medium object is set to be excluded, the resulting image can have visual errors.
  • Cutaway material does not allow scattering medium to be seen through the cutaway material.

Geometry nodes

Some geometry may not show Flakes/Bubbles.


Some CAD formats i.e. .3dm, .c4d may be imported as several triangle groups and then merged making the body unfit for Flakes/Bubbles.

Workaround: Import with NURBS and Re-Tessellate.

Geometry nodes don't respect disabled state.
Raytraced textures (Contour, Curvature and Occlusion) cannot be used to control parameters of any of the Geometry Nodes.


When applying Displacement to geometry with hard edges, these edges become split.


Hard model edges become split. Left cube is with hard edges, on the right the cube has a small fillet on the edges.

Workaround: Applying blends in CAD usually solves the issue.

Area Light

ZSpheres transferred from ZBrush are not supported for Area Light

Multi-Layer Optics

Multi-Layer Optics do not support nested dielectrics/liquid interfaces.

Scattering Medium

Overlapping objects with Scattering Medium may have shading issues.

UV Mapped Textures

UV mapped textures applied to NURBS objects in Rhino are not mapped properly



Depth of Field

Panoramic Camera behavior is significantly different when "Use GPU (enable effects)" is disabled in Preferences

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