1) got it

2) the thing is, although there are 3 fields (x, y, and z), each of those should contain thousands of values (like an array? - one for each pixel). With the code you recommended, it just gives me [0,0,0]. When I connect samplerInfo.pointWorld to a shaders color property, I get the desired distance to color mapping for each pixel, as it should. But it seems at any one time, there is only 1 value for x,y,z stored in samplerInfo.pointWorld. I need ALL of them.

Does that make any sense?

Thanks,
Dave