Blender Discussions

[gelert]

Plane: Uber Coating set to reflect the cubes above

Cube 1: Uber shader with Transparency = 1

Cube 2: Simple Diffuse cube

Cube 3: Simple Diffuse cube with RPR Settings Casts Shadows + Camera Visibility turned off.

Cube 4: Same as Cube 3 only with another Sphere object dissecting the Cube - showing the "darkening effect" of the supposedly invisible cube.

Problems:

Cube 1: Cuts a hole in the plane displaying the background colour of the scene. It should not do this.

Cube 2: Correct

Cube 3: Should not display a reflection or cast a shadow.

Cube 4: As Cube 3 but it is also darkening the sphere as if it is casting a shadow.

All of these issues above also exist on any Simulation Domain box.

[bsavery]

It's a good test case. 

1 and 4 seem like the might be core renderer bugs.  But I'll mention workarounds:

1.  Add a bit of distance between the cube and plane or use a smaller ray epsilon

2.  Use a transparent shader

3.  I think is a feature request that we should expose the "reflection visibility"

[gelert]

It would be awesome if you could expose the reflection visibility as a new feature. Combined with being able to turn off the camera visibility it enables some brilliant visual effects to be created.

There is also the problem that on Cube 4 somehow the cube's internal shadow is changing the colour of the sphere. That may well be fixed if the cube was truly transparent via the core renderer fix.

[martinackerl]

This is my result on iMac pro with internal Vega64.

[bsavery]

Thanks for the testing.  I think most of these should be fixed with the upcoming bug fix release which will have a "reflection visibility" option on the object.  #1 We're still investigating.

[gelert]

Result in v1.7 250 on macOS. Core renderer issues still present. Image is identical to iMac Pro output though. Mine was eGPU x 2 on MBP 15 inch.