You’ll need Flash Player 10 for these demos to show corrently …

Doing a diffuse shading with graphics.drawTriangles(): the principle is to connect two shapes,
one with normally wrapped texture and one with shading:

To get the actual shading I’m using a bitmap-stripe with different shade values as the texture:

The u-coordinate for shading mapping is defined by the dot-product, = cosine of the between-angle, of the vertex normal and vector of light direction, from values near 0.0 in the dark parts to 1.0 on the brighter areas. Similar to Gouraud-shading, the color from the vertices is interpolated over the triangle by drawTriangles(). Using a bitmap as some kind of lookup-table also allows easy control of brightness, contrast and light color. Notice that I’ve used a very dark blue at the darkest parts to simulate ambient light and give the shape some extra depth (Africa in the image below).

and here’s the resulting image – and demo, two layers combined with blendmode ‘hardlight’ :

… source for globe-demo

… for comparing an earlier demo of a rotating globe with pixel bender

Ok, rotating cubes and spheres, seen it: let’s have some more advanced shapes, the classic Stanford Bunny with 500 vertices and mesh of 1000 triangles – in fact the smallest I could find on the net, the texture mapping may not be the best possible, the model had no uv-data, so I applied a simple sphere-mapping:

An Eagle with a mesh of 1500 triangles – hope it’s not after the bunny:

Update October 9, 2008:
Things are getting funnier, and the bunny’s getting bunnier: it’s gained some more weight, 2500 vertices with 5k triangles currently, and still keeps on rolling – this time with only the shading layer, but it does process through all the 2.5k vertices and normals and update the shading each frame :