CGTalk - Image sizes for UV's?

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Bangladesh

09-02-2003, 10:42 AM

Hi!
First off, I'm very new to texturing (or to 3D-modeling for that matter) and really need some advice and hints on UV-sizes. I'm using LW by the way.

My problem is that I have two different and separate UV-maps for my character; one for the head and one for the body (so far, it might be more before I'm finished).

The problem occurs when painting the texture, since I'm just experimenting the textures are both 1000*1000 large so the body-texture is of course "smaller" than the head-texture.
I get seams where the two maps meet even if the color is the same on both maps. Why is this? Shouldn't a flat, plain color be the same while rendering even if the texturemap is smaller? :surprised
As it is, the body-map becomes darker than the head-map.

If this is the problem, how can I set the correct scale on the maps realtive to each other? Or do I have to put everything on the same map, unwrapped in the same size?

Grateful for any advice I can get! Thanks!

HapZungLam

09-02-2003, 08:50 PM

i don't quite understand what do you mean by UV size. But according to Leigh's tutorial. Your texture should be 4 times bigger than your object will show at your render. Say if your object will be super close up to the camera, and it will be render as 640, then your texture better be 640x4.

in the other hand if that's going tobe way far from the camara, then it will be way smaller.

But if your character is for game. that's usually 512x512 or 1024x1024 for the texture size that's for everything.

Invader Zim

09-02-2003, 11:16 PM

The pixel ratio where your 2 texture sheets meet are not the same. Meaning, the texture sheet for your head has more definition then the rest of the body - pixels are smaller.
Hope this helps you.

leigh

09-03-2003, 12:16 AM

Hmmm the difference in size shouldn't be affecting the colour... tell me something - are you applying both UV maps to a single surface applied to your model? I find that in LW this causes problems.
Try using a different surface for each UV map. And if you already doing that, then check to make sure that the Diffuse levels are the same on each surface, as this is the only thing that would make the one darker than the other :)

Bangladesh

09-03-2003, 10:03 PM

Thanks all for helping, I've checked and tried the things you all suggested and it got better. The best result I got was with Zim's tip, simply enlarged the texture, but it's hard to tell exactly when the two texture-sized meets up so there's still a seam although not too visible. Why exactly beats me since it's only flat colours but... oh, well as long as it works. (I reassigned the UV's and got that "2 UV maps to a single surface"-problem Leigh mentioned. Kinda funky! :) )

In the end I took the easy way out and made a surface with a base-color and then applied the textures with alpha-maps to hide the seams. It quick and it's dirty but it works... in a Aretha Franklin kinda way. ;)

Thanks a bunch for helping!

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