View Full Version : Weird bump map artefact when at subdivision 2?

06 June 2008, 07:16 AM

I'm new to XSI and am doing some texturing tests.
When rendering a normal map as a bump map, I get a strange artefact when the model is at subdivision level 2, but I do'nt get it when the subd level is 0 or 1 or 3 (see images).

Is this a known bug in XSI or am I doing something wrong?
Thanks ...

EDIT : I've just noticed that I do get artefacts at other subd levels but in other places!
Is my nodes setup wrong ?

06 June 2008, 08:26 AM
I've never seen this bug, but it looks like a UV problem.

if you are using normal maps, you should use the XSI Normal Map node, instead of the bumpmap.
in the rendertree: Nodes>Bump>Normal Map

Always pay attention to what UV you set to the map, as I can see in the first image you didn't set any.
This should work normally even if you don't set. But it's always good to let the right UV selected in there, in case you add other UV projections etc...

Also how did you generate this UV? it looks like was generated in Model space... But I don't think this could cause any problem.

06 June 2008, 08:35 AM
Hi tc and thank you.

I guess I'll have to study the manual a bit more before getting it right.

I had tried the normal map node but didn't get it to work and I did get it to work with the bump map node.

Th uvs are generated in modo and I imported the model as an LWOfile.

Wow : there's so many things and settings to pay attention to!

Do you know of any XSI tutorial by any chance for applying normal maps?

06 June 2008, 09:28 AM
Problem solved : when generating the normal in zbrush i have to make sure "tangents" in "normalmap" is on.

06 June 2008, 09:30 AM
Silly question, did you generate a tangent space map for the object when applying the normal map shader?
Because XSI kinda needs that. ;)

Get>Property>Tangent. ;)

06 June 2008, 05:32 AM
Hey Maph, no not a silly question because I did not!
Now that I'm aware of tangents I now what to study in the manual and available resources.

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06 June 2008, 05:32 AM
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