Bump map disappears at particular view angle

[Sacha]

I have a problem with bump maps.. when looking at an object with a bump applied, at some view angles the bumps become invisible. I tried a lot of settings and searched through the forum for a while now but it seems, nobody else has that issue.
When I take the cam looking from the upper side, you see, how large the bump is already set... too large. but when moving the cam down it disappears.. the same happens with the bumps on the side of the chair, when moving the cam more frontal....

any hints would be great!!



aqua

[vlado]

It's probably because of the texture filtering; you can try reducing either the global filtering multiplier value in the V-Ray settings, or the Filter parameter in the Effects section of the File node itself.

Best regards,
Vlado

[Sacha]

Hey vlado,

I already tried that.. Also I tried to turn the filter completely off but the behavior stays the same. the bump gets a bit rougher but it still disappears when viewing at a special angle. For now I applied the bump as displacement but that´s not really the way it should work, because i already have some displacements added and as I already told in another thread when working with a layered texture and putting exr files as different displacement maps on the object, the "allow negative colors" is not transported from the displacement map to the layered texture. So I 'm not able to get even one good shot. From every angle of view one surface has a missing bump =(

It's probably because of the texture filtering; you can try reducing either the global filtering multiplier value in the V-Ray settings, or the Filter parameter in the Effects section of the File node itself.

Best regards,
Vlado

maybe you can look at the layered texture problem? Just place two exr files with positive and negative displacement on an object an see that just the positives are calculated.. That would help a lot.

thanks
aqua

[bigbossfr]

Yep, the layered texture clamp all textures (i haven't tested with the "allow negative colors").

[Sacha]

Yep, the layered texture clamp all textures (i haven't tested with the "allow negative colors").

I have =) in the vray globals and also in the textures node.. maybe we need an xtra Vray attribute in the layered texture itself!?

[vlado]

I have =) in the vray globals and also in the textures node.. maybe we need an xtra Vray attribute in the layered texture itself!?

I don't think so... the clamping is applied (or not) on the input data read from the bitmap file; once this is done, the Layered texture works with whatever data is passed to it. You can try using another node, like +/-/Average, it may work better for your purposes.

Best regards,
Vlado

[vlado]

maybe you can look at the layered texture problem?

I'd rather look at the original problem with the bump disappearing; however I would really need a scene where I can reproduce the effect - if you can get me some part of the object and the specific camera angle where this happens, it will be very helpful.

Best regards,
Vlado

[Sacha]

I'll send you some pieces in the evening..

[Sacha]

hey vlado,

so it took a bit longer =) I append a scene file with every maps included. Looks a bit confusing, but I placed some other maps on the objects to be shure it wasn't the texture. When you open the scene ans use the persp2 cam you'll see that the bump on top of the armrests is not visible.

best regards,
aqua

ok... the file size limit is way to small.. I sent it by email

edit: grmpff... email doesn't work either... do you have any adress where I can upload the file to? its about 24megs

[Komposer]

did u try the bump delta scale slider?
a value of 0.2 or so...

[Sacha]

did u try the bump delta scale slider?
a value of 0.2 or so...

yep I also tried that.. just like changing the filters it only makes the bump a little rougher but not better. The problem is, if I modify the texture so much, that I can see it in the special angle, it gets way too strong on that faces been okay before... and if I change the texture itself by changing the dependent parts to get what I want, it will just fit in that angle of view. as soon as I move the camera everything would be wrong again, because it seems not to depend to the texture but to the camera-object-angle - maybe in conjunction with the texture.. I'd send vlado my files but I need an upload adress where I'm not limited to 90k

best regards,
aqua

[bigbossfr]

Megaupload ? Rapidshare ?

[vlado]

I'd send vlado my files but I need an upload adress where I'm not limited to 90k

If you email us to vraymaya@chaosgroup.com, our support guys will be able to send you details how to upload it on our ftp server or, if the scene is a few megabytes, you can send it directly to vraymaya@chaosgroup.com

Best regards,
Vlado

[Sacha]

If you email us to vraymaya@chaosgroup.com, our support guys will be able to send you details how to upload it on our ftp server or, if the scene is a few megabytes, you can send it directly to vraymaya@chaosgroup.com

Best regards,
Vlado

Hey Vlado,

I just uploaded the file to your ftp.

best regards,
aqua

[Metzger]

Have you tried using a V-Vray bump material? Throw your base material with no bump in, then put the texture to the map slot and render. I notice if I'm not happy with the bump on the V-Ray shader I use this and get totally different results.

This is with the latest stable build.