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Maaahshoe
12-16-2005, 11:16 AM
Hi,

I've no idea of how todays games are being textured. I'm talking about large out door or even indoor environments. What game brought me to this question what World of Warcraft. Was an in-game screen shot of a stone path that was flowing along the side of a mountain. The path had a texture and where the path met the grass on the side, there was another texture that seamlessly blended the two. As if the grass had been cut and worn. The path also had flowing bends the the textures were perfect.

Okay now to the questions.... Q1. Do they make textures for the curvy bits of the path? Q2 The seamless texture transition of the grass to the path texture, how?

I had an idea that a tested and seems to work but I'm not quite sure and coming to you guys to get some real answers. My idea was vertex colours. Editing the vertex colours of the environment mesh and using it as a map for mixing textures. Is that crazy???

This has been bugging me for a while even though I'm not in game development I am very interested and always wanted to know. If someone could give me some answers I'd greatly appreciate it.


Matt

ChimpanG
12-16-2005, 02:20 PM
could you show us a screenshot?
having a guess at what your talking about its probably one of these:
1. there is a map that is black/white and tells the engine to draw texture1 and texture2 for black and white, then the artist makes the edge of the path fade from black to white and there you have it, a nice fade.
2. a technique i thought up the other day (it exists already afaik, but i though of it while experimenting) there is an in-betweener polygon, so you have.
[tiling path][inbetweener][grass]
the inbetweener is half of each with for example the edge of the grass where its been cut down the middle to seperate them.

might post a screenie of that later.

Brain Trepaning
12-16-2005, 08:53 PM
my website http://trepaning.com (http://trepaning.com/) the Doom 3 section has a video tutorial on blending terrain textures http://trepaning.com/d3Vids/tutorials/d3_blending_terrain_textures.zip Variant of process is used for many engines

Janimation
12-16-2005, 09:59 PM
Possibly vertex alpha along the paths verts? to blend it to the ground below?

cholbrow
12-16-2005, 10:43 PM
There are many ways to do this. In 3ds Max you can use a "mix map", or in Maya with a "Blend colours" ( you can also do this with vertex colours like you said)

To get to this in max just plug a Mix mapp in the diffuse channel.
Colour 1 and Colour 2 are your two maps and the mix amount determins how transpartent the top map is. The nice thing about this way is you can use diffent map channels or UV sets for each map. Thus you can have two tileing maps mixed together with a non tileing black and white image to hide the fact that they tile. (also the black and white image can be low quality as you wont notice)

http://www.vertexpirate.com/pics/Tut/mixMax.jpg

In maya its called a Blend Map or Blend colours. As you can see its almost the same set up. To get this click on the colour channel of a new blinn (or whatever) and under Utilities is Blend Colours. If you want to have more then one UV set for the mapping its a bit more tricky then in max. You have to go into the Relationship Editor>UV linking to tell maya what uv set controls what texture and so forth.
http://www.vertexpirate.com/pics/Tut/mixMaya.jpg

I dont think that either of these programs will do a great job of displaying this in the viewport. At anyrate this is a useful tool for solving all sorts of problems. Like for example mapping a sphere with no seams or polls, or saving texture space with environments.

eMPeck
12-18-2005, 07:48 PM
Depends on engine.

Some of it allows to use mix map based on RGBA channels:

http://reality.artificialstudios.com/twiki/bin/view/Main/MixMapTutorial

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