Texture bake "Projection" issues

[rainingwaffles]

We're unable to get projection baking to work as expected in V-Ray 4.04.03 in Maya 2018.

Attached is an example scene with a cube and sphere intersecting. The cube has a yellow VRayLightMtl and the sphere is invisible to camera with a standard lambert. In this scene, with projection set to "closest" we expect the sphere to bake completely yellow, but in this test it instead renders black when using projection baking with Lighting / Shading -> Bake with VRay (options) -> projection baking checked, bake.

Toggling different projection modes in the vrayBakeOptions, these are the results:
* Outside Geometry -- Black
* Inside Geometry -- Shows some yellow, seems to be rendering the geometry outside the sphere (opposite of expected)
* Outside First then Inside -- Black
* Inside First then Outside -- Same as inside
* Closest -- Black

And rendering through the global Baking Engine Settings -> "texture baking" looks like it only renders the inside geometry, where we want it to render closest.

So the main questions:
* Is the projection baking behavior broken?
* Should the global "texture baking" setup use closest geometry or is it something different?
* Can the projection baking options be fixed and honored from the global texture baking? -- the reason this is important is the Lighting / Shading -> Bake with VRay doesn't seem to support V-Ray DR.

Thanks for the help!

[rainingwaffles]

To add more data, reversing the normals on the cube and using "closest" in projection baking gives a completely yellow texture, which is what we want. But the normals of the shaded geometry on the sphere should NOT affect the result of the bake; we want the bake to always calculate the shading based on the surface normal of the closest point.

[nikolay.kusht]

At first look, it seems that the VRaylight material does not have the option "Emit on the back side" enable. This is the reason why baking the sphere with a "closest" mode is not producing the correct results.

I will further test the other modes to see if they are working as expected and let you know.

[nikolay.kusht]

After further investigation, it turns out that the "Inside Geometry" mode for the Projection Baking options is not producing correct results. This affects also the "Closest" mode as well since this mode is using the logic from both "Outside Geometry" and "Inside Geometry". This was added as a bug to our system(VMAYA-8788 ).



As a workaround, and to mimic the "Closest" mode, perhaps you could make one bake with "Outside Geometry". Then flip the normals of your object and do a second bake with "Outside Geometry". Combining both bakes should produce the correct results.