Metallic principled shader renders black about ospray_studio HOT 9 CLOSED

Thanks for pointing out the difference in our material implementation. We're considering a change to conform. We'll let you know if/when things change.

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You have the specular set to 0.0. Set the specular value to 1.0 and you should get the look you're going for.

With OSPRay's Principled material, specular and metallic work together

    const float conductor = metallic * specular;

https://github.com/ospray/ospray/blob/5269850081d1c7d6da59b3c4f3cbac5c732374ba/ospray/render/materials/Principled.ispc#L319

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Hello,
Thank you for your quick answer! Quite unusual for me, but I'll try to cope with it.

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If I might ask, quite unusual in what way? If you'd prefer, when you have a material with metallic > 0.f, just don't specify the specular and OSPRay will default to 1.f.

All of the default values for OSPRay's materials are listed here https://www.ospray.org/documentation.html#materials

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In all the renderers I know, the metallic parameter of the Principled shader is independent of the specular parameter.
To illustrate, here is the same scene as above, with metallic=1 and specular=0, rendered with several other renderers (source files attached below pictures):

Appleseed:

(appleseed.zip)

Cycles:

(cycles.zip)

Luxcore:

(luxcore.zip)

.

I was expecting the same behavior from Ospray, that's why I said "unusual". Anyway, the tip you proposed should do the job, thanks!

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[Reopening]

I modified my Project to comply with the above requirements (metallic 1 and specular 1).
The rendering is better, but there is still a problem: some faces remain black:

I suspect a problem with the normals (especially since, when I invert them in Transform menu, the black faces and the rendered faces are switched).
However, inspection of the OBJ normals in Blender does not reveal anything wrong:

Could someone help me please? Many thanks in advance!

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I'm not quite sure what's going on, but it is not unique to OSPRay. If I import your 3 objects into Blender and render with Cycles, I see the same thing. Orienting just right you can see the blackness sweeping over the top face -- interestingly it's not along the triangulated diagonal either. One of the side faces has this same error.

The default cube (using quads, in the foreground) does not show this error.

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Thank you for your responsive answer! I hadn't thought of rendering the whole scene in Blender, I'll look into it

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You were right, there is a problem in the OBJ file (with the normals). It's about the exporter, not OSPRay. So, I close this issue, thanks again for your answer!

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