How to Paint game textures

#101

Originally posted by Dunbar
So if anyone could hop onto that thread and shed some light for a good basic lesson on alpha maps, that would be GREAT!
and would add much to the cgtalk.com community. :slight_smile:

I suggest you guys to share the info here, and not on separate threads!
This is what this thread is about, to collect the information, so everyone can get it here, who want’s to know more about texturing.
Specific info goes to individual threads, common goes here.

Question: Has jpeg any advantage over the other formats (in relationship of game engines and texturing)? I assume loading time may be faster. Where can you use it effectively, since quality is lesser? I assume, for less detailed, noisy things like grass, mud, stone, organic stuff, but not for exact things or characters.

#102

I use a Graphire2 4x5 and it works quite famously. Many many artists and such will tell you that you don’t need a large size tablet. I know some who had 4x5 tablets, upgraded to a larger size, and switched back to the smaller size because it’s more convenient.

#103

file size difference might not matter much in terms of video memory, but processing time should be better.
Not true. Video cards (whether in a console or PC) mostly accept just raw pixels coming in, so the game engine converts whatever compressed format you are using into raw uncompressed pixels before sending them to the card. Same processing time, same video memory load, no matter if you use compression or not.

One common exception is the DirectX Texture format (DXT or DDS). As I understand it, some cards support keeping these in compressed form in video memory, uncompressing them in hardware to render them. So the files take up less room both in storage (on the harddisk or CD) and in memory (on the card).

Some info here about DDS, worth slogging through the technical jargon…
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/directx9_c/directx/graphics/programmingguide/gettingstarted/direct3dtextures/compressed/compressedtextureresources.asp
There are quite a few DXT flavors available… compressed vs. uncompressed.

Some nice examples of DXT texture issues on UDN…
http://udn.epicgames.com/Content/TextureComparison

I’ve heard there are other card-supported texture formats too, but they’re mostly confined to one chip manufacturer or another.

So for me, JPG is usually a waste of time, since it is lossy and doesn’t support alpha and doesn’t stay compressed in memory. But I guess if the hardware doesn’t support DXT or somesuch, or you’re developing with a web-based engine, then JPG might be good.

There are also paletted textures, those with 256 or less colors. Often you can get away with a 16-color palette for detail textures, effects and the like. Gray textures are sometimes best as 8bit paletted files, for example lightmaps or bump maps.

Hope that helps.

#104

Just thought I’d brag about Lightwave a bit…

What I do a lot with my models is set up the UV’s as best I can and then go back in later and do touch-up’s with planar maps. Here’s what I mean:

  1. I set up say, a leg. The UV seam is on the inside of the leg.

  2. After I paint as best I can, there’s still a little seam (or the seam is REAL ugly), so I set up a planar map of the seam and the area around it, and I use surface baker to export all the color information to a .tif

  3. I fix the problem in photoshop using the clone tool, paintbrush, etc.

  4. In Photoshop, I create an alpha map for the fixed seam picture.

  5. Back in Lightwave, I add another layer to the pants texture, slap the fixed seam pic on there, and then blend it into the original UVmapped texture using the alpha map.

  6. Use surface baker to export the color information back out to another .tif, this time using the original UV Map.

Presto! Seam fixed. May be a little complex, but when I get some pictures up you’ll see what I mean.

#105

Thanks for the post! Similar technique here for 3ds max, if anyone’s interested…
http://www.neilblevins.com/cg_education/map_channels/map_channels.htm

#106

Oi sorry for the absence! I don’t think I’ve been back here since that post. I used to come for the competitions and just ran out of time to do them…

You can grab the brush file here. Make sure and right click and “save target as”

Heres the difference:

Also UVmapping in lightwave rocks. :slight_smile: Actually everything in lightwave rocks… cept there aren’t enough game format exporters for it. :frowning:

Seams: Use a test pattern like a multi colored checkerboard. That way you can spot misalignment and distortions problems early and fix the map accordingly. If you can’t actually adjust the map (ie its a premade model you are skinning) the test pattern still helps, or make a separate layer in photoshop, and put evenly spaced tickmarks in a very visible pattern along the seam areas you are haveing trouble with so you can see just how to adjust your details or lines to match one another in position.

#107

Hi everyone, individuals know and have experienced so much here that I was wondering if anyone had any ideas or tutorials on how blending two different maps for use in an environment is done for games. A good example i can bring up is in the pic i have attached. The grass seems to blend into the dirt and vice versa. Does it have to do with the way the geometry is laid out on the map…or is it a type of procedural texture that was created in the material editor. I’m using 3D Max if that helps any, but of coarse any help, dierction towards reposts like these with answers or tuts would be gladly appreciated. Thanks!

Screenshot taken from Bungie’s Halo.

#108

Usually vertex-alpha-color is used for this kind of blending. So there are triangles defining the path, with four edge-loops defining the path, two on each side. The vertices along the two outer edge loops use a vertex alpha color that blends in the grass texture, while the two inner edge loops use a color that controls the path texture. The distance between the two inner edge loops defines how wide the path will be, while the distances between the inner and outer edge loops defines the mixing area between the two textures.

Unless Halo is using something new and esoteric I guess…

#109

Hey Eric thanks for the reply…I know exactly what you mean by the edge loops…my main concern i guess is that i can’t seem to make the textures blend. I may be confused…but i keep questioning myself by saying, well how are they blending when only one diffuse texture can be applied to to each poly? Its not as if they applied the grass all over and then applied the dirt where they saw fit. That would get rid of the grass in those certain areas. As you can see in my example i am using one 1024x1024 texture that contains both the grass and the dirt. I have unwrapped the box so that the grass is shown on the sides and the dirt in the middle…but then how can i blend them? As you can see the grass stops to meet the dirt. How can i use the vertex alpha coloring to make them bleed unto each other? Hope i made myself clear. Thanks for the help.

#110

I’m not sure how Bungie implemented their vertex-blending scheme. Usually game devs develop their own standalone art tools for things like this.

In max you can use a Vertex Color map in the Blend slot of a Blend material. But that only lets you blend two bitmaps at a time…

#111

Ah, I searched around a little, here’s a method for storing multiple vertex color channels, so you can use multiple Vertex Color maps… which then could be placed in a Composite map or somesuch.

#112

Thats multi-pass texturing… I just finished up a game on the Tony Hawk engine, and it has support for 4 multi pass channels.

This layers up to 4 textures onto the same piece of geometry… on PS2 each layer is an actual piece of geometry thats created through enabling multi pass texturing… on GC and X-Box its almost free…

The setup above is pretty common. For the transition area, you would just have multi pass texturing setup on 2 layers, and vertex alpha through one to the other…

Some engines have a harder time with this… Renderware is one that comes to mind. In that case, when you use vertex alpha, the alpha wont stop at the base texture layer, but continue all the way through the geometry… so you gotta find a work around.

Anyhow… you can do some cool things with it…

#113

Vailias: Thanks for the brush size idea. I set my brushes up like that and I can tell you it definitely speeds things up a bit.

Yeah, Lightwave is great at everything. And I have complete faith that once game companies take the time to check it out, Lightwave is going to be a major player in the game development field. Take normal mapping for games, for instance. Every time I turn in my portfolio lately the first question I get asked is what program I used to make the models. I don’t know what the procedure is in other prog’s, but in LW all I do is make the hi-res mesh first, copy it, drop the polygons, create a normal map, and bang. Next generation game model in no time flat. Not to mention I just bake the hi-res texture to a single map and I have an instant texture. Too bad every good company uses 3dsmax.

#114

Great work on the brushes layout vailias. Has helped me a lot already. Thanks man.

#115

Alright, I have some questions to toss in here:

  1. How much shadow should I be putting into my maps? I’m new to texturing for games, so I’m unclear on this. I know that some games prefer almost no shadows on the maps and let the vertex shading handle it. What’s a good amount of shadow on a texture map? I’ve just been shading anything that the geometry doesn’t show (such as wrinkles in cloth, etc)

  2. How long should it take you to finish a map (professionally)? I’m used to spending days on a single texture (for film), but I want to retrain myself for games.

  3. Cloth. I’m looking for good techniques on the finer points of clothes, like how to draw in the little stitches on denim, to how to make a good collar, etc.

4)Is there any way to view the texture maps they use in games? I know that UnrealEd will view those, but what about games like Jedi Knight 2 (or Academy)? Is there a program or a way to view those texture files? I’d like to study them to get a better sense of UV Layout, texture detail, shadows, etc.

Any help is greatly, greatly appreciated!

#116
  1. IMO, depends on the quality of the lighting technology in the game. Almost all current games use very simple point or infinite lights, maybe mixed with some ambient or somesuch. If you have normal mapping and better lighting, you’ll want very little shading since it can fight with the “real” light. But if just normal maps without strong lighting tech, you’ll want to bake in some GI shadow-gathering-in-creases kind of shading. And if no bump mapping, then lots of baked-in light will help (ala Quake III).

  1. A good read…
    http://dynamic.gamespy.com/~polycount/ubb/Forum8/HTML/003291.html

  2. Some tehcniques here…
    http://www.planetquake.com/polycount/cottages/qbranch/tutorials.shtml

  3. Far Cry demo stores all the tex in PAK files which are really just PKZIP format. Many games do this. After unpacking, get the DDS tools from Nvidia to see them.
    http://developer.nvidia.com/object/nv_texture_tools.html

Many artists who work on games show flats on their sites. BoBo the Seal is an example…
http://www.bobotheseal.com/images/mods/q3f/engineer-final02.jpg
David King is another…
http://www.planetquake.com/polycount/cottages/kingscastle/gallerytexture.htm

Hope that helps. Maybe someone else will chime in with their thoughts…

#117

I am rather curious but, how do you paint teeth texture maps? Thanks in advance…

#118

something like that?

picture shows color, specular and normal maps.

i’m afraid there’s nothing special about painting teeth (at least for me) that separates it from texturing other body parts.

#119

Yes…I want to do that for game models and stuff like that …

#120

[QUOTE]Originally posted by GIJoe
[B]something like that?

How did you make the normal map for this?