View Full Version : UV mapping problem

02-23-2011, 02:28 AM
Hello everyone,

I have a problem with UV maps. Lets suppose that we have a piece of terrain. This terrain has a UV map called "terrain". Everything is good until you select a streak of polygons, delete their UV from the "terrain" map and map them to their own UV. The problem is that after you merge points, the points in the "terrain" UV that were connected to the polygons of the streak reconnect again. How can this issue be resolved?

02-23-2011, 05:32 AM
Hi TRUFFLE, welcome.
LW UV can be tricky, i posted a pdf way back about solving issues like this. http://www.newtek.com/forums/showthread.php?t=95400&highlight=tutorial

Anyway, here is that apllyed to an object similar to yours that it's more simple than the pdf.

02-23-2011, 10:20 AM
Well everything is ok until you unweld and merge them again. This can be a great problem when working with characters for example - you merge and unweld the model a lot.

02-23-2011, 10:35 AM
If you unweld and merge all points alot, the fix that i shown you won't help, since those red discontious points will be lost on unweld and when you merge the UV will be 'patched'. So you either:

- Grab the polygons you don't want in the UV scale them down to a point size and put them in the UV origin or some other corner. (this way it won't try to make the geometry every time you merge it cause it's already there. In the end you can delete that point/s if you need.)


- Do the UV only after you do whatever makes you unweld and merge.


02-23-2011, 11:10 AM
Doesn't selecting, cutting then pasting the geometry/UVs before merging fix this problem? I tend to just use PLG UV Edit and create my UV islands. As a result, I never run into this issue.

02-23-2011, 12:15 PM
This always happen, i think, if you have an UV Island with with discontinuous points all around and no regular points in between (a bit like the Edge Bevel issue)


If he adds an interior edge loop on that specific L shape, he will have no problems with this, but i don't know if he wants that.

02-24-2011, 02:34 AM
I know that interior edge loop fixes the problem but it is not the way out for it means increasing the number of polygons in that area. And if I just leave those polygons mapped on the original UV and scale them to some corner it means that they will be mapped on both UV maps. This doesn't seem to be the right way and can cause troubles with some game engines.