BruceSherwood
commented
10 years ago The same problem applies to curve, and there doesn't seem to be a way to do anything about it. The statement f.pos = f.pos[:-3] could just as well be f.pos = array([1,2,3], [4,5,6], [7,8,9]); in other words, we have no idea what portion of the color or normal arrays to use in the truncated object. A possible approach would be to create a new method: f.truncate(i,j) would replace the current pos, color, and (in the case of faces) normal arrays with pos[i:j], color[i:j], and normal[i:j].
If you truncate faces.pos, the color and normal arrays are also truncated, but incorrectly. As you can see in the following example, the pos array loses its last 3 elements, but the color and normal array lose their first 3 elements.
from visual import * p = [(-1,0,0), (1,0,0), (0,1,0), (1,0,0), (-1,0,0), (0,-1,0) ] c = [color.red, color.orange, color.yellow, color.green, color.cyan, color.blue] n = [(0,0,0.1), (0,0,0.2), (0,0,0.3), (0,0,0.4), (0,0,0.5), (0,0,0.6)] f = faces(pos=p, color=c, normal=n) print('------------------') print(f.pos) print('------------------') print(f.color) print('------------------') print(f.normal) print('**') scene.mouse.getclick() f.pos = f.pos[:-3] print(f.pos) print('------------------') print(f.color) print('------------------') print(f.normal)