Weird triangles at the edge of a layered UV map.

[kretin]

This is exactly the same problem as you had earlier. If you don't include all the polys of a surface in a UV map, or at least an extra row than you need, you'll get this problem occuring at the edges of the UV map.

[LittleFenris]

I have a UV map that covers the entire head (minus the ears) surface and this 2nd UV on that surface is just the polys on the top of the head to cover up the cylindrical pinching of the UV map below it. I don't see why this isn't working.

[kretin]

If you send me the model I'll show you what I mean, but essentially the top layer UV map needs to include more polys in it...

[leigh]

As Kretin said, this is exactly the same problem you had the other day - it always happens if you don't make your UV maps correctly.

I would highly suggest that you read the section on Vertex Maps (UV maps are just another type of vertex map) in your manual because you don't seem to have a good grasp on some of the concepts of UV mapping yet :)

[LittleFenris]

Originally posted by kretin
If you send me the model I'll show you what I mean, but essentially the top layer UV map needs to include more polys in it...

I would have to send you all the textures and all wouldn't I? Thats like 48 MBs in stuff. The model itself is only like 500k though. I would have no problem sending you the model if you can help me out here. I just don't understand why this isn't working. All selecting more polys is gonna do is make that weirdness happen in a different spot isn't it?

@Leigh - Thanks for the suggestion, I'll read that tonight. (I have NO IDEA what I'm doing with UVs or texturing in general really. I have always modelled stuff and never got far enough to texture. I intend on animating this model to get a taste of all the aspects of Lightwave. I have modelled stuff, now I need to figure out texuring, then onto animating, then lighting, then rendering. Man, there is a lot to this stuff. :eek:

BTW, the problem I was having before was because I was trying to put a UV map over the edge of two different surfaces. I don't understand why a UV with an alpha isn't working with its all on one surface now. :shrug:

Also, if the UV is setup wrong, why does that weirdness only happen on one side of the texture and not both (since the model and UVs are both symetrical)???

[kretin]

no man, just the model is enough... although it may help if you sent me the textures for the head.... even low-res versions... even just the offending texture...

The problem before wasn't related to putting a UV map over 2 surfaces, or 1 surface. It's related to the points in some of your polygons not belonging to the UV map...

Hard to say why it's only happening on one side without seeing the model, wireframes, UVs etc... I can tell you more after looking at the model....

[LittleFenris]

When I get to work in the morning I'll send you the model and the two head textures. Thanks a lot for any help you can provide!!!

[LittleFenris]

Can anyone else help me figure this out? I have put the model online with the textures in a lowres JPG format so the alpha channel is seperate from the texture since its a JPG. the actual textures are TIF files with the alpha channel built-in. Here is the link to the files if anyone can help me figure out why those Triangles are happening.

http://vwtornado.baked.net/Fenris_Web/Files/

Basically the head texture is a cylindrical UV map of the whole head, minus the ears...its the base texture. Then the Head stripes are a planar UV map (on the Y axis) that I made to cover up the pinching you see from the cylindrical map underneath. The alpha channel is actually part of the TIF file I have at home (seperate JPG file online for file size sake). Any help is GREATLY appreciated and will be duely noted in the final animation. :beer:

[Locutus]

Your already talking to two of the best people you can find to help you with this problem, dude.
Everyone else is going to tell you the same thing.
Reading the LW7.5 Help file will also help.

:cool:

[leigh]

VWTornado, I just can't seem to get rid of those triangles for you (sorry about the delay by the way, I was having some problems with my system) - I can't seem to understand why they are happening on the one side only.

I'm sure the answer is simple but I can't seem to figure it out (my brain is a bit sore tonight).

The only thing I can suggest is to have it like that, and then use the Surface Baker shader to bake the entire colour channel (all the layers with different UV maps, in other words) to one of the UV maps (use the head one). Then open that new image in Photoshop and paint out any artifacts that have occured.

This will work perfectly :)

[LittleFenris]

Hmm, I've never used Surface Baker...I'll give that a whirl. Thanks a bunch for the help Leigh (and kretin), you rock! :buttrock:

[leigh]

I did exactly what I just recommended, and it does indeed work exactly how it should.

Setting up the surface baker and baking the images out to the Head_UV uv map gives you an image that looks like this:

http://leigh.cgcommunity.com/temp/rocco_head_tex.jpg

And when used as the ONLY texture on the head surface (remember to disable any alpha channel that the Surface Baker creates in the image), you get this:

http://leigh.cgcommunity.com/temp/rocco_render.jpg

As you can see, the image is automatically distorted to fit the pinching of the cylindrical map, but then works perfectly because it is basically a compensation and therefore undistorts when rendered.

Woohoo! :D

[kretin]

Hey VWTornado,

Here's my fix showing what I meant about adding the other polys of the surface to the UV map...

http://www.zerogravity.com.au/temp/Rocco_UV.jpg

I've emailed you the model...

[LittleFenris]

First off, Kretin, you rule. That fixed the problem!! :D Second, Leigh kicks some serious butt also. :buttrock: Thanks a lot for the help. How can I view the polygons that are in a specific UV map? Also, how can i change a UV map that is already made...like add to or subtract from an existing UV map? I know I can select the polygons in a surface with the statistics panel, but what about polygons in a UV map?

Now Kretin, why does selecting all the polygons in the head surface fix those triangles? And why was it only happening on one side of the UV map (thats the part that really baffled me)?

And for Leigh, I tried the Surface Baking and got those exact same results...my only question now is...see the wierdness in the stripes on the top of his head? Why is that happening? Like, see how its kinda jaggy (like the stripes are being shook back and forth real fast) in the middle of the stripes? Also...when YOU bake a surface...how do you work with the crazy spots where LW has compensated the texture to fit and it makes it all weird looking like the top part of the surface baker image? Do you just leave it alone in those areas and just fix the parts that were messing up before (like my triangle spots)?

Once again, a HUGE thanks to both of you for your help!! :beer:

[leigh]

How can I view the polygons that are in a specific UV map?

What I usually do is simply go to the UV viewport, and select the polys in the UV map itself.

I'd still recommend that even though Kretin has successfully solved the triangle issue (I think the triangles appearing on the one side only have something to do with discontinuity), it would still be a good idea to use the Surface Baker to create a single texture to use, since less texture images = less rendering time :)

[LittleFenris]

Originally posted by Leigh
What I usually do is simply go to the UV viewport, and select the polys in the UV map itself.

I'd still recommend that even though Kretin has successfully solved the triangle issue (I think the triangles appearing on the one side only have something to do with discontinuity), it would still be a good idea to use the Surface Baker to create a single texture to use, since less texture images = less rendering time :)

Thanks, didn't even think to select them that way. Now my other stupid question is how do I get the UV map I want to show up in that UV map viewport? :blush: (if its in the manual tell me and I'll read...I have the LW 7 manual in front of me) Also...same as my question before...I tried using Surface Baker but it seemed to add some issues of its own in certain spots. And I agree...less rendering time = good. :D

[leigh]

Now my other stupid question is how do I get the UV map I want to show up in that UV map viewport?

Haha, just change one of your viewports in Modeler to UV Texture (although I'm assuming you've done this already), and then at the bottom right hand corner, you'll see some buttons labelled W T M. Click on the T one to activate textures, and select the UV map from the green drop down menu that is initially labeled None :)

I tried using Surface Baker but it seemed to add some issues of its own in certain spots.

What sort of issues?

[kretin]

As Leigh said, to select the polys in a UV map, change one of your views to UV and select the polys in there...

The problem is caused by polygons that aren't included in the map sharing points with polygons that are included in the UV map. You can see the image below with the main head texture turned off that it is happening on both sides.

http://www.zerogravity.com.au/temp/Rocco_UV2.jpg

What's happening is that the points of the polygons not included in the map are being UV mapped. Because not all of the points of those polys are included you get these errors. You could just as easily just include one more row, making sure that entire row is 100% transparent according to your alpha texture. That will ensure that the next row of polys after that, even though they will still have the same problem, will render transparent...

To fix up your surface baking, you'll need to edit your UV map so it's neater. The problem is occuring at the top of the head where you have both back and front polygons sharing a single point. You can see in the UV map how the polys are stretched. If you fix that your baked image will appear much nicer.

As a general rule, jump into the UV map once you've created it and move points around to clean it up. Especially when using a cylindrical or spherical base for your UV map you'll usually run into some problem areas with the default map that need neatening up. If you create a UV map without cleaning it up you might as well be (and would be better off) using standard mapping.

BTW If you clean up your UV map you'll find you won't even need this alpha map at all as you won't get that nasty texture stretching then :)

[LittleFenris]

Man, you both rock. What would I do w/o the awesome people on this forum. :buttrock: I Guess I would be stuck with a badly textured kitten. ;)

edit: Here's an updated render of the whole model so far. :buttrock:

http://vwtornado.baked.net/Fenris_Web/JPGs/Rocco_Samurai.jpg

[CGTalk Moderation]

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.