TEXMAP Fallback

[Travis Cobbs]

In order to keep a good surface for the texmap, there needs to be a good match between triangles and condlines.
A pattern line across a condline will result in a non-smooth surface and a bad surface for the texmap.

That's only true if you don't use texture-specific geometry, and don't have an actual FALLBACK section in the TEXMAP section. When the vector geometry is complicated, it belongs in a FALLBACK section that doesn't get rendered at all when TEXMAP is enabled. The geometry that gets textured would then be done via 0 !: lines.

So, if the vector geometry is really simple (or nonexistent), then the part can have something like this:

Code:

0 !TEXMAP START <params>
<simple shared geometry>
0 !TEXMAP END

The <simple shared geometry> section will render in both TEXMAP-supporting renderers and renderers that don't support TEXMAP. On renderers that support TEXMAP, the texture will render over the geometry.

In my opinion, as soon as there is any vector geometry, the following setup should be used instead:

Code:

0 !TEXMAP START <params>
0 !: <simple textured geometry>
0 !TEXMAP FALLBACK
<complex vector-only geometry>
0 !TEXMAP END

This means that only the simple geometry will be rendered when TEXMAP is enabled. Even with your example with the simple globe, I would argue that it should be done this way, and not draw the TEXMAP over the vector geometry, even though that vector geometry is relatively simple.