Dave wrote:
> Hi. I am learning PyOpenGL and I am working with a largish fixed scene
> composed of several thousand GLtriangles. I plan to store the coords and
> normals in a NumPy array.
>
> Is this the fastest solution in python? would i be significantly better
> off (timewise or otherwise) using some other data structure to hold this
> information? no other data structure appears as convenient, but am i
> loosing valuable time?
>
> I am new to 3d programming so please feel free to state the obvious,
> thanks.
>
There are two major approaches you can take:
* array-based geometry -- this relies on fast memory-transfer rates
operating a C speeds
* display-list-based geometry -- this relies on moving all of the
data over to the card
If you can reduce your entire (static) scene to a single display-list
call, you'll likely find that it's faster than using array-based
geometry. If you have special effects (e.g. transparency), then you'll
likely find that coding as array-based geometry is the more practical
approach.
By way of reference, OpenGLContext uses array-based geometry throughout
these days. I had (at one point) code to make individual display-lists
out of particular indexed face sets, but it didn't provide any
performance boost when applied at the single-object level (i.e.
thousands of display lists with all the traversal code still required),
so the code is now disabled. Simpler (static) scenegraphs where there's
lots of traversal between nodes should be a much bigger win for
converting the whole thing to a single display list.
HTH,
Mike
--
________________________________________________
Mike C. Fletcher
Designer, VR Plumber, Coder
http://www.vrplumber.com
http://blog.vrplumber.com
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