UDK - Lighting tileable modular building issue!

m1neh

Hi All,

So I'm trying to create a modular building set for a sandstone wall. I started with just a basic bare wall which tiles in Max:


When imported into UDK it looks horrible, with some kind of lighting error like this:

I don't want to move onto the other parts until I've got to the bottom of this so any help would be greatly appreciated!!

Cheers

Nielsen

Yes this is unfortunately one of the issues you'll run into when building these type of walls. Your best bet is to try and make the surface area of the front of the block as large as possible on the light map or model in real brick and deform the surface at the points where the walls will be meeting to hide the seam and lastly increase the lightmap resolution / lightingbuild quality to make the lightmass process more accurate.

You could also make a few variants of a larger size so the seams will be less prevalent. So 2 blocks, 4 blocks in a row etc.
and cover them up with decals / other things such as pillars.

m1neh

Fixed! Was a lightmapping issue - Had to make a lightmap as second channel in Max, split all the polygons and move them apart from each other.

HAWK12HT

Hmm interesting you get the result after just setting lightmaps, but here is the thing I would like to point out, use or make seamless texturing on the sides (front) of walls than you wont see the repeating patterns like in the middle of your wall.

m1neh

They are seamless, it was just the lighting which made them seem to be badly tiled, see fixed:

m1neh

I see what you mean now, thanks for the feedback!

m1neh

So, this issue is back again, with a slightly different part of the modular set!

The window block is causing issues with the lightmap, and I simply can't find the fix online. I've seen the video where the guy does it with floor planes, but it isn't that simple with this.

So here is a screenie of the issue:



To solve the normal block, I simply created a second UV Channel, disconnected every single face, and gave it a decent amount of space. With this, its not so easy, due to the triangular parts enabling me to cut out the centre of the window. When I try that method, it gives me some even worse lighting issues! So I'm back to square one with this annoying shadow running down the seam. As you can see from the image, my lightmap is composed of two parts, the wall mesh and the window mesh (they actually have completely separate material ID's when imported so I'm technically using two different materials on the one mesh). My lightmap res is at 32, and raising it does decrease the effects, but even at very high res the problem still persists subtly.

Any help would be massively appreciated!!!!!!

Cheers

m1neh

Solved again! :P used the same technique but kept the main body together, the important part to have space left with is the bit where the mesh is going to join the other mesh on a flat surface, those edges need to be the seams in the lightmap. Can give more detailed advice if anyone needs it

HAWK12HT

hmm dunno how u gettin lucky with this , would like to know more though on ur findings. After much sturggle and separate UVW maps for all faces the seams were there one way or another (with without Normals) After much reading on forums and also checking out the video of the guy (long time ago) you are talking about it didnt help me. So i did my own thing and here are the findings im comfy with so far but would be nice to know if u can completly solve seams on solid pieces.

m1neh

I have found that where flat polys meet, that specific edge must be on the outside of a UV Island, with plenty of space around it and not touching the edge of the 1x1. With a bit of messing around with the lightmap res this should solve these horrible shadowed seams. I understand that putting some indents on stuff also stops this, but sometimes a man just needs a flat surface! Am i right?

tristamus

So overall, if I understand this correctly, the highest priority for having no seams in UDK is to make sure the edges of your UV shells are not too close to other UV Shells? And to separate UV's entirely?? Is it really always necessary to separate all the UV's?

Ken Benson

If you have not seen this yet, it might help...

http://www.polycount.com/forum/showthread.php?t=93055&highlight=lightmap

I especially enjoyed the video posted there.

m1neh

Ken Benson: That video is going to every thread about lightmaps :P

For me, it was a bit more complicated than that because firstly: I was not just using a plane, and secondly because I have no idea how you are supposed to know you are exactly on a pixel with perfect accuracy.

Tristamus: It's not necessary to break every single UV, its simply the face which is meeting another face with a completely flat surface - thats where the errors occur, and thats when the the edge needs its own UV space around it.

Sometimes breaking up all of the UV's can work, but if possible you want to have stuff stitched up where you can, if for nothing else than to save on UV space...