From: Jonathan B. <jbr...@ea...> - 2007-01-26 23:59:36
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On Thu, 2007-01-25 at 12:53 +0100, Ting Li wrote: > Hi, fans, > > I'm a newbie. > > VPython is really easy to use. But it looks too simple. > I wonder if there is a parameter to customize the number of faces used > to draw a sphere (or cylinder ...)? I cannot find it. By default, > VPython draws a pretty smooth sphere, I guess the number of slice > should be larger than 50. > > Sphere(pos=(*,*,*),color=color.red) > > However, low polygon objects are needed. This control is necessary to > make smooth animation, especially when the number of objects is large. > > I know VPython gives a way to build object by user, face. > But can the authors make life easier? > > Another question is also about the rendering efficiency. > I don't know if VPython uses gllist internally. VPython 4 uses GL displaylists, whereas 3.x uses vertex arrays (still fairly fast). > (sorry, haven't > studied the source) ,and if VPython support object 'instance'? (A > instance of an object doesn't need to rebuild the vertex array at a > new position but just copy the vertex from the original object and > perform translation, scale, or zoom. ) Where possible, objects share the same geometry to conserve memory and for speed. Objects with instance-specific geometry include arrow, ring, curve, convex, points, and faces. -Jonathan |