Smooth Landscape Textures

Thank you very much.

But how can I set the alpha value to the maximum at the top and to the minimum at the bottom?

By calling SetRenderState()?

I only know to set the alpha value for the entire blit.

Bye,
Michi

Why not use texture synthesis and do all the hard work beforehand? Then you don''t have to waste band width on multi-texturing or multi-pass. http://ddg.sourceforge.net has a class called ddgEco that will synthesize many textures into one parametricly. It takes a heightmap, textures and elevations limits as input then spits out a brand new texture. So far its based on elevation\slope but with some tweaks you can get it to mix textures at the same elevation. I have a sneaky feeling it does this anyway if you use the randomize flag.

Hope this helps.

Kallen

Or, you could draw the "transition tiles" by hand, if you want to have some variation.

-Jussi

For my terrain, I am basically doing what Anon suggests. To achieve the fade he describes, you have to set the alpha value of each vertex''s diffuse color component. Then, you set the texture-stage state alpha-op to "select arg2" (assuming your arg2 is the diffuse).

Two other things: I think Anon is mistaken -- you should first render texture A with 100% alpha across the entire face, then render texture B with a fade from 100% to 0%. Also, I used multi-pass instead of multi-texture; it''s supported better, and there are relatively few polys in my terrain that need to be rendered like this, so the speed loss is minor.

ive been trying to do this for a while and unfortunatly havent been able to,
2 textures.
A == grass , B == rock , blend the two together based on a third greyscale texture that serves as a blending amount modifier, eg like alpha. ive tried various methods of multitexturinbg getting quite close but not perfect. anyone got any answers?

btw the problem with prerendering everything first, is it''ll need a heap of texture memory though of course it''ll be way quicker to render.

>btw the problem with prerendering everything first, is it''ll >need a heap of texture memory though of course it''ll be way >quicker to render.

Well with a little more work you can break a large patches into small tiles and do paging of textures. This way your only loading the unique textures you need. If you go for one large height map with an accompanying large texture then yeh your gonna have problems as its wasteful.