Reflections without textures

[F Suarez]

Hi everyone. I’ve been rendering with Vray for some time, but recently I’ve been trying to get better results, adding some reflections, and I’m having some problems. The biggest issue I encountered is that sometimes instead of reflecting the texture I’m using, there’s a white area in its place. I’ll put an example below.

 

As you can see on the left of the first image, instead of reflecting the wood texture, as it should, it simply shows a white area. I’m not sure if it’s a bug, or just a basic mistake I’m making somewhere.

I’m still using Vray 1.49 (for SkethcUp).

 

I’d appreciate if someone can say if this is supposed to occur.

Thanks in advance for all hints and suggestions.

[Chris MacDonald]

Firstly all of your normals are backwards, fix that first.

[F Suarez]

Hi Chris, thank you for your post. I may be completely wrong, but as far as I know, I'm not using normal maps. The only thing I made was to create a reflection layer. I think the image may not be completely clear, because in the image above not all surfaces have a reflection layer, it was my attempt to get rid of the problem.

 

I just made another render, to be easier to identify the problem. The first image that I'm attaching to this post has all the wood surfaces using the exact same texture, which has a reflection layer. I'll attach below also the settings I'm using.

 

 

The ONLY thing I changed from default was the TexFresnel > Perpendicular, from white to grey.

 

 

Thanks again for your help, I really appreciate it.

[Nicolai Bongard]

When Chris mentions normals he is referring to the front and back side of a poly/mesh. Usually when creating for example a cube, you want all six faces of the cube to face front/outward. If you invert/flip the normals(front/back side of a poly), strange stuff can occur.

[Chris MacDonald]

Hi Chris, thank you for your post. I may be completely wrong, but as far as I know, I'm not using normal maps.

 

Surface normals and normal maps are two completely different things. What I am talking about are surface normals, which is the direction of the polygon; front and back faces.

 

In Sketchup the White/Blue faces aren't there for fun - they are there to show you which normals are backwards. White = Front face / Blue = Back face.

 

This may not be the cause of your problem, but it is the first thing you really need to rule out, because it will cause you problems with refractions, if not reflections. Select the blue faces, right click them and select "reverse faces".

 

 

It also is very difficult to see what it happening in your render, perhaps increase the exposure to get a better look at things?

[F Suarez]

Thank you very much, Chris and Nicolai. I reversed the faces and indeed the problem got solved. Thank you both.

It''s funny that I've been modeling for years and only now I had this problem. It surely won't happen again.