Specular Material Artifacting Tweet

[Bowser16NB]

I am getting strange artifacting on an fbx object imported from zbrush. I've done several remeshes and reimports of the object but it's fairly simple geometry. See all attached images to see issue.

The issue appears when I have a specular material applied to the object. When any of the other materials are applied it works fine, ONLY specular material is where I'm seeing the issue.

Does anyone know what is causing this and/or offer up a solution?

C4D Version: R18.057
OctaneC4D 3.08.2
OS : Windows 10

[bepeg4d]

Hi,
we have solved this issue via support ticket.
In general, when you are having unexpected results with Specular material, first thing to do is to switch the Kernel in InfoChannel mode, enable the Wireframe backface highlighting option, and choose the Wireframe type:

In this way, the flipped normals will be displayed in red.
If there is an issue, it is also possible to use other InfoChannel types like Smoothed Normals to spot it:

If you invert the polygon normal direction, everything works as expected.
In Shading normals:

In Wireframe:

And in Pathtracing or with any other Kernel:

ciao Beppe