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View Full Version : placing a decal


leonlabyk
03-29-2006, 04:01 PM
I have created a polygon motorbike based around the one in akira and am having difficulty applying the decals to the model. I was simply selecting the face on the object i wanted to place the decal and then applying it by selecting a lambert and then changing the colour to that of the decal. This comes in all distorted though due to the fact I am obviously doing it all wrong. I am totaly new to cg and any tips or links would be much appreciated.

JaMo
03-29-2006, 09:24 PM
have you layed out your UV's?

cgtriguy
03-29-2006, 09:29 PM
There are a few different ways to do this. The key is to get the UV's laid out properly. I assume you are using an image file for the decals, though it doesn't really matter. Assuming you have the UV's laid out well there are a couple of things to keep in mind. First, when you assign a shader to individual faces it still assumes the UV's are part of the larger mesh. In this case you either need to create the texture with the UV layout in mind or you need to change the UV layout to match your texture. This is a little bit hard to explain in words.

Your texture/shader is going to want to cover the entire 0,1 UV space no matter how you apply it to the model. So if you have a 512 x 512 texture it will not distort over this space. If you have a 512 x 125 then it will stretch the 125 out to match the 512 and there will be distortion. To avoid this you can export the UV map to a file then load it up in photoshop and create the texture there so that the decal overalys the correct UV space. Then when you assign that shader the faces you want you know it will appear properly.

The other option is to assign the shader as you have then select the faces that it is assigned to and open the UV Texture Editor. Then repostion the UV's to match the decal. If you are not famliar with the UV Texture Editor then this will not make much sense. I actually prefer this method as it allows me to use much higher resolution textures for important areas and low res for the others.

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03-29-2006, 09:29 PM
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