Iray "Reflective Metals" Rendering Black
inthanity
Posts: 89
Hello,
I have some objects in a small room scene, specifically drawer pulls and door handles, that are using Iray Metal Shaders for their Surfaces. Regardless of which reflective/glossy metals I seem to try - nickel, cobalt, polished aluminum - they all render black. I am using Iray Light Probe Kit to illuminate the room (there is no ceiling though), and so the lighting does not seem to be the issue.
See image attached. Any suggestions?
Post edited by inthanity on
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Comments
did you check the materials to see if there is a color or texture in the gloss or top coat color?
Are the other walls there?
Do you have the render engine set to "Iray" and not to "3DL"?
@Sorel - there are no images set for those settings in the Surfaces Editor, just the default settings connected to the standard Iray metal shader presets.
@RichardHaseltine - the scene is enveloped by all four walls, yes.
@Sylvan - the render engine is set to "NVIDIA Iray."
What product is it? Did you apply different shaders or is it the default?
I created the objects in Photoshop, extruded the objects in the 3D menu, and exported them to obj files. Then I imported them into DAZ3d, applied the Iray Uber Base, and then tried applying a number of the metal shaders - all to no avail.
I also have a flat surface that has the mirror shader from ShareCG applied but it renders black as well.
Attached are the settings for the drawer pulls.
I didn't know you could make objects in Photoshop, but I'm wondering if in the process perhaps you flipped normals in the OBJ objects?
Create a sphere primitive, apply the metal Iray Uber preset to it, scale down and move the sphere primitive so it is next to the handle, then render. That will help determine if it is an issue with the geometry or something else like the lights or render settings.
use the geometry editor to select the handles and then in the geometry editing setting select flip normals and see if that changes anything.
First off, change "Glossy Color Effect" to just "Scatter". Scatter and Transmit is not appropriate for metals. Things like glass and gems, but not metal. You also need some glossy roughness. For metals I'd advise at least .20. I would also further suggest you not have any color chips at pure white (or anything at pure black for that matter either).
Laurie
@sorel & @ebergerly - I tried the "flip normal" in the geometry settings and it made no impact in this case. Thanks for the advice.
@robotheadart - I set a sphere with the same Iray Shader presets adjacent to the drawer, and it rendered black as well. See attached. Thanks.
@AllenArt - thanks for these suggestions. I will try these shortly and let you know.
The surfaces that aren't all black, can you check what shader is being used for those surfaces? Is it the iray uber or something else? The all black (especially on the primitive) looks like what you get when the shader information isn't present where Studio is looking for it.
@AllenArt - I gave that a whirl and it still renders black; no change.
@AlmightyQuest - other items that aren't black show "Shader: Iray Uber", just like the objects that render black. The problem appears to only happen with items that bear attributes of reflectivity. The problem is that I need these items to be reflective, whether the mirror on the wall that is rendering black, or the metal handles that have some reflective quality.
On your render settings tab, can you check under Optimization to see what "Max Path Length" is set to? I tried the default polished aluminum shader by the way, which is the one it looks like you first used, and it is working, and my surface settings look like your screenshot.
Thanks @AlmightyQUEST,
My Max Path Length is set to 2.
I'd expect more than just black, but try setting it to "-1" and see if you get better results. (negative one basically tells it to not limit that)
That did the trick, @AlmightyQUEST, thanks!
Doesn't that increase render time?
Good idea to use it to check for the issue but I might now set it at 4 (and increase as necessary if the problem persists)
Or is Iray clever enough to stop tracing when it no longer makes a difference?
@SilentWinter & @AlmightyQUEST,
The -1 setting did increase my render time significantly. Setting it to 4 works as well, and I am going to see what the render time is for that setting.
Thanks for the help.
7 to 9 is a good compromise between render time and good reflection. (personal judgement based on personal testing).
Thanks @fastbike1 .