Shader Oddity with Ancient Boards - Weathered Wood and Plank Shaders for Iray: Solved!

paulawp (marahzen)

While testing some new items I bought lately, I ran into a weird problem I've never noticed before with a shader. It's the Ancient Boards - Weathered Wood and Plank Shaders for Iray:

Ancient Boards - Weathered Wood and Plank Shaders for Iray | Daz 3D

I often just create a primitive plane to check out new shaders, and I was doing just that. I had just tested two other new shaders I've bought in the last week, and they worked as expected when I applied the shader to a plane, viewing and rendering in Iray. Then I got to this shader, and I found that the plane is invisible to Iray. Not a sphere or a cube ... just the plane. I tried different various material choices, I deleted the original plane I had been testing with and created a new one, I've tested with a material in this set that I confirmed works just fine when applied to, say, a sphere. I even created a new scene, in case I had introduced something wonky from testing previous new items. No luck. It's invisible in the viewport when using Nvidia Iray (though perfectly visible when using something else, like Texture Shaded) and when rendered, is just black.

Has anyone ever seen this? All I had was a basic plane from Create -- New Primitive.

Spacious

It sounds like you may have come across a shader that has just a smidge of negative displacement.  On a plane placed in the default location that will cause it's surface to be just below the imaginary ground line.  If you've got the iray Environment settings set to 'Draw Ground' and 'Show ground from below', which are the default setting, I believe, then you won't be able to see your plane because the displacement will be pushing it below the ground.

Try rotating your plane so it's oriented vertically, or just raise it ever so slightly so it's not below ground.

Or I could be totally wrong.

barbult

Or just turn off Draw Ground for a quick test. You will see that the plane is properly textured by the shader. @Spacious has identified the problem, I believe.

paulawp (marahzen)

You are both right. It works fine if I uncheck Draw Ground or rotate it. I've not seen that before! Now I know. Thanks!

Spacious

It's notable that the invisible auto ground plane gets placed at the lowest point of any object or figure in your scene and will move automatically to match that point.  It's designed to give you shadows in an HDRI dome environment for example, but can also be used for interesting effects combined with this phenomenon in conjunction with displacement.  I found it by accident at first, just like you, and was frustrated by it as well.