How to change anisotropy direction in object, not in shader

Become a member of the CGSociety

Connect, Share, and Learn with our Large Growing CG Art Community. It's Free!

Thread Tools Search this Thread Display Modes
  06 June 2013
Question How to change anisotropy direction in object, not in shader


I have a doubt and probably its easy to solve, but I tried to find a solution all the day and I couldn't. The problem is that I have an anisotropic metal shader assigned to some objects, but the anisotropy rotation is not the way I want in some of the objects. I have to change the anisotropic rotation only in some objects, but keep it in the others, so I think I can't change it directly in the material.

Any advices on how I can do this rotation of the anisotropy in each object?

Thanks in advance.
  06 June 2013
Why can't you copy the shader so it's separate from the original. Then change the direction and re-assignment the new shader to those specific objects?
  06 June 2013
I can do it. And I can also use the Anisotropic Rotation map, but I would have to paint a texture manually. I know the two ways aren't very difficult, but I thought maybe there's some attribute in each object where I can set the value to 90 degrees, or some trick I could do in the UV Texture Editor, because I know that if I use a planar projection I can define the way the anisotropy will happen depending on the axis of the projection.
  06 June 2013
Rotate the UV.
I sign here?
  06 June 2013
When I rotate the UV, I rotate also the brushed metal texture in my bump map and I shouldn't rotate it.
  06 June 2013
Originally Posted by gustavopch: When I rotate the UV, I rotate also the brushed metal texture in my bump map and I shouldn't rotate it.

This is how I usually do in that case. One brushed metal texture in a shader with anisotropic direction the same way as the texture. UV all the polygon with that shader to the desired angle.
If you really don't want to or can't re-texture or re-uv, I believe you will need to split the shader as other have stated.
I sign here?
  06 June 2013
you can create another UV set (multiple UV's), one specifically for the anisotropic direction that you can rotate the UV's while leaving the others alone
  06 June 2013
I've attached a scene with a singleSwitch utility used to change the anisotropic rotation per object. The switch was really designed for input textures so just to switch between single values(instead of textures) is less obvious. I created an expression that sets the input values on the switch(see expression1 in expression editor):
singleShadingSwitch1.input[0].inSingle = 0; // anisotropic rot for the 3 connected objects
singleShadingSwitch1.input[1].inSingle = .2;
singleShadingSwitch1.input[2].inSingle = .4;

I think it can also work to do setAttrs on these attributes, but one can more easily see and edit the values, while the attributes are not displayed in the channel box or attribute editor.
  06 June 2013
Sorry for the delay and thanks for the answers.
I don't know a lot about expressions and nodes in Maya, but I understood a little about Duncan's approach. Next weeks I'm going to deepen my studies about these two things and probably I will completely understand the approach.
sentry66, how would I tell to the material that the second UV Set is to be used for the anisotropic rotation?

Sorry for my newbie questions and thank you all again.
  06 June 2013
Thread automatically closed

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.
CGTalk Policy/Legalities
Note that as CGTalk Members, you agree to the terms and conditions of using this website.
Thread Closed share thread

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Society of Digital Artists

Powered by vBulletin
Copyright 2000 - 2006,
Jelsoft Enterprises Ltd.
Minimize Ads
Forum Jump

All times are GMT. The time now is 04:08 AM.

Powered by vBulletin
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.