Well Ill use this thread anyway, because I had just the same idea, to experiment with different heights for every corner in a tile map, and I have the same problem, applying correct lighting and textures. On one hand, I would appreciate any more ideas considering the problem. On the other hand, I’d like to share my ideas so far:
My first attempt would be using a simple flat texturing, so that the texture is not perspectively morphed but just clipped to the tiles shape. And to create the look of depth just using lighting / shadows on each tile. That could be done by manipulating the image data and lighten or darken pixels row by row, or painting a fading from light white or black to transparent over the tile. Anyway, one really needs to buffer the result and do the texturing only once, everything else would be to slow.
My attempt number two would be writing my own texture routine. I have the book from David Brackeend and he describes 3d software rendering and texturing. Using some rather simple math is already enough to calculate the position of each point of a texture to a destination point on the morphed tile. For each different shape and texture, you’d need to at least one apply the texture to the tile shape by calculation each pixel value using 3d math. You probably want to buffer the resulting images, for you cannot calculate this every frame.
The problem here is not actually texturing but perspective morphing. Isometric graphics use some simple math to produce results that look like having a perspective. When you consider it the way a 3d engine does, each tile is a flat shape with some angle along the 3 axes. There is some math involved in projecting a shape in 3d into a view from a given point of view. The basic calculations for 3d transforming can probably found on the web.
-JAW
