[socalgal2]

they are doing completely different things.

shadertoy: given a pixel coordinate, write a function to return a color.

geotoy: write a function to return vertices

In shadertoy, to draw cube on a 1280x720 screen requires your function to be called 921k times. To draw a cube in geotoy requires your function to be called 36 times. That's over simplifying but saying one is fast and one is a slow is comparing atoms to balls. Shadertoy = describe every atom, geotoy = describe the shape. again, bad analogy I suppose, but the orders of magnitude difference are somewhat help explain why one is fast and one is slow (yes though, you can generate a geotoy that will be slow and a shadertoy that will be fast). Similarly describing every atom means you can describe fog or god rays or caustics etc. Describing the shape won't do that.

PS: I think geotoy is cool. nothing above is meant to detract from that. Just to explain, probably poorly