bug with Boolean / Create single object

[lenogre]

In the viewport, it's perfect : colors are at the right place.
But after render, some colors disappear.

The guilty party is the option "create a single object" in Boolean Object. You must desactivate this option to prevent this bug.

[iacdxb]

Color seems me fine only in single object I am getting correct shadows which I am not get without single object...!

...

[lenogre]

Picture with red arrows is good.
Picture with green arrows is wrong (grey color by default).

Which picture is with Single Object ?

I'm with C4D 19.

[PROH]

Unless it's a selilluminating material, then it's definitely the picture with green arrows that's right! The red arrow pic shows no shadow on the inner side of the hole.

[Eddoron]

have you tried manually collapsing the resulting meshes into one and then use the optimize function to weld the points?
I wonder if there's still the broken result.

[iacdxb]

Using R18, OS X.

I think it should be same render result with or without single object...!

...

[lenogre]

You can notice some holes have lose their color : that is the bug.

[houska]

When the boolean is resolved and the "create single object" option is enabled, a single object is created from all of the sub-objects and all the material assignments are put onto that simngle object. Now, with the material stacking, we limited the number of materials on one object to 64, because that should be enough for everybody, right? But it turns out that you can get over this limit very easily with boolean objects. In the current release candidate, the limit is raised to 256, but we will remove it altogether soon.

[lenogre]

OK, understand.