Okay. Thanks. Lights are continuing to come on...

So...would you typically take your base skin (i.e. the one in which I've already painted roads and grassy areas and stone areas in the higher moutain parts, etc) and somehow convert that base image into an image that will communicate to the shader code how to blend onto the .hmp a combination of 3 or 4 textures? If so, do you typically drop the use of such a base image as being overlayed over the entire terrain (i.e. not scaled), or can you use it both as one of the four textures (not scaled) and also tweak a version of it into your alpha map?

Or...would you start with your grayscale image you used to create your .hmp in the first place and use that as your base image?

Also...am I right in understanding that you could have a shader that blends four different textures depending upon the RGBA channels? The one I'm using blends two textures. Are there any examples out there of ones that make use of all four channels?

Thanks guys for your help. It's getting clearer, but obviously some of this stuff is still fuzzy for me...

Peter

All depends on what you need and are most comfortable with - and what your shader dictates. I generally prefer to work from the concept (all the textures in place and working) to the individual parts. You can do this by using channels in Photoshop to act as masks. This way you can see more or less what the composite skin will look like in 3DGS. After I get what I want, I make sure the channels are in the proper RGBA positions and then go ahead and save it out as my blend map for use in the shader.

http://steempipe.technicalfoundry.com/terrain/terrain.html (example of shaders using more than two textures on the terrain)

In theory you could use as many seperate textures as you want. Each one needs to have its own channel for blending though (and you could add more and more blend maps till you drop to 1 FPS and 200+ MB of memory being consumed). In practice though, you should probably stick at or around the 3 or 4 mark. Anymore and you really start to take heavy hits on the FPS as the textures are processed.

Thanks. That helps as well. And the link I had seen before but it makes more sense now.

Separate but somewhat related question: is there a way to cast shadows from models onto the terrain? Including the player walking around?