Weird Reflections

[bob-cat]

Stainless steel fridge which looks like its got folds in the door?
This is the 3rd time I have re-modelled this, cleared all smoothing groups also and ofcourse the obvious mad sure its all dead flat.
Anyone know how to fix this?
Max 2009 64 Vray 1.5 R2

Cheers

[bob-cat]

Ok sorted it out.
I set Anisotropy back to 0.0 and all good.
Thanks for the help

[joconnell]

It's a good point though - I had something modelled very cleanly and ran into similar issues. What's the fix for it?

[MoonDoggie]

Geometry problem, retriangulate or remodel the front.

[bob-cat]

I also thought it was a geometry issue, but as mentioned I remodelled it 3 times (just the face of the fridge) with no change, the folds marks changed depending where the triangle edges were.
Maybe I should of deleted the frdige and start a fresh.

But what did fix it was I set the "Anisotropy" in the BRDF roll-out of the material back to 0.0, it was set to 0.5 to get the stretched reflections. Maybe "Anisotropy" only works corectly with the Ward shader (I had it set to Blinn)?

[bob-cat]

Needs a bit more samples and maybe a bit too shinny, but the folds are gone!

[joconnell]

It's strange - I did a brushed metal light switch with all quads - I expected that the topology was causing issues and it didn't do a great job of resolving. Not to worry.

[Codi]

The folds are still there, just less noticeable.
What mode are you using to for the UV vector derivation setting in the material BRDF rollout? I've tried with different local settings (X, Y and Z) and I can't reproduce it, but using a map channel can render those problems if the object isn't properly mapped.

[stevesideas]

I had exactly the same problem with a mesh I was applying antistropic reflections to. The mesh was clean, quaded and just like every other model in the scene yet it rendered in a similar way to bob-cats image. The object was uvw mapped as well (Like I do every other model). What are we doing wrong ? Vlado ?

[vlado]

You need to use the mapping channel option for the anisotropy derivation; also make sure the face of the fridge has separate UVW vertices from the sides (if it is attached to the sides at all).

Best regards,
Vlado

[joconnell]

Ah - that's interesting - say for example if you've got something where you've got a softly rounded edge where would you break the edge? Would you leave all the flat faces as one section in the unwrap uvw, the rounded bevel parts as another and the flat side sections as the last? Is vray interpolating across the normals of all the faces when using anisotropythus causing the mess ups?

[vlado]

Is vray interpolating across the normals of all the faces when using anisotropythus causing the mess ups?

Yep - it has no way of knowing where to stop.

Best regards,
Vlado

[bob-cat]

Ahhhhhh.......... the penny droped, now this makes sense, thanks.

[joconnell]

Yep - it has no way of knowing where to stop.

Best regards,
Vlado

Super - that's going to solve a lot of render issues from now on!