Re: [pygame] Blended tile systems

[Casey Duncan <casey@xxxxxxxxxxx>]

On Oct 14, 2008, at 1:25 AM, Knapp wrote:

> > I think you are talking about something very similar to "texture  
> > splatting",
> > described in excellent detail here:
[..]
> of time for each texture tile.
>
> Does this make more sense now?

Sure, using texture splatting would give a bit more of a naturalistic  
look. It accomplishes much the same thing, you use arbitrarily large  
textures for each type or terrain and "splat" them onto whichever  
tiles have the terrain type corresponding to the texture. Adjacent  
tiles of the same type are seamless and the individual tile "squares"  
are not obvious. Using OpenGL means I don't do "blitting" per-se, I  
just calculate the mesh vertices and texture coordinates. The latter  
are basically just continuous. Then the texture for each tile type is  
laid down masked by a "splat" texture that only lets it show through  
in the appropriate places. I don't draw each tile individually,  
instead chunks of tiles are drawn at once, with nearly all of work  
happening in the hardware. Since you are redrawing the same mesh  
repeatedly, you get nearly ideal throughput from the graphics card  
which typically has caches that optimize this case.

[..]
> Are you talking 2d or 3d?

The map is strictly 2d, but the rendering is 3d. The textures do not  
have any depth by themselves (e.g., there are no mountain or canyon  
like textures), instead height variations are represented by the  
height of the tile mesh. Note that you need not do it this way, you  
could instead have a simpler flat mesh and shade the textures to give  
the illusion of height like in your example.

> > It does support arbitrarily large maps by dividing the mesh and  
> > textures
> > into chunks, so it can draw only the visible chunks. It does not  
> > support
> > more advanced features like automagic LOD control, which isn't  
> > useful for an
> > iso game not drawn in perspective.
> >
> > I don't have a screenshot of the current code handy, but I could  
> > post one if
> > you like.
>
> You mean a screen shot of the pictures the code makes right? Yes, I
> would love to see that.

Here's an example screenshot. Note this map is fairly flat and doesn't  
really show off all of the different terrain types, but it gives you  
the general idea:

http://picasaweb.google.com/casey.duncan/Mechazoid#5257032978315813906

-Casey