black occlusion wierd normal

[bradon]

I have an object with the normals pointing out. diffuse renders fine, but occlusion renders black. If I flip the normal the occlusion renders fine but the diffuse renders black. so its seems to be somehow the mesh is flipped but I can't figure out how to fix the mesh so both work at the same time. its nested in a scene with other objects so i cant simply flip the normal in the occlusion node.

anyone had this problem? seems to show up for me every once and a while. if its easy I just rebuild the mesh. but its a pain to do that everytime.

[mr furious]

sometimes point and face normals get messed up... an easy way to check which way the normal is facing with out turning on the normal gizmo ... turn off 2-sided lighting this will cause the back side of polys oppsite of the normals to be back.

in polygon mode look at the Normals Window (drop down) and give the following a try....
Select Mesh
1. unlock normals (this will cause your mesh to look faceted)
2. conform
3. set normal angle (re smooths the mesh)

hope that does the trick. This can especially be a problem if your using point cache. (at least that's what i've found)

A

[Yannick]

Might be worth checking that you don't have the Vray physical camera on.

[bradon]

bingo. many thanks

sometimes point and face normals get messed up... an easy way to check which way the normal is facing with out turning on the normal gizmo ... turn off 2-sided lighting this will cause the back side of polys oppsite of the normals to be back.

in polygon mode look at the Normals Window (drop down) and give the following a try....
Select Mesh
1. unlock normals (this will cause your mesh to look faceted)
2. conform
3. set normal angle (re smooths the mesh)

hope that does the trick. This can especially be a problem if your using point cache. (at least that's what i've found)

A

[Metzger]

Also, you can turn on reflect on backside, or double sided in the shader/vrayDirt.

Vray is a normal nitpicker.