Hi there,

I just did some tests according to the comparison of a single, big mesh and
a structure of unions of small meshes.
The results are quite surprising.

I rendered a single wing with 40 leaves in 320x240 AA 0.3 in highest level
of detail (auto LOD settings turned off)
The picture was quite distorted since I removed any transformations beside a
single alterating horizontal shift of the leaves.

Single mesh variant:

85 objects (the stem was still included)
Parsing 1:20 (min:sec)
Tracing 1:04
Total 2:24

Complex unions:

11762 objects (full detail!)
Parsing 1:32 (only slight difference since code is unchanged there but some
more calculations)
Tracing 1:35 (slightly slower)
Total 3:07

As I could observe, in the union test (original code) tracing got faster to
the end. Obviously POV removed bounding boxes which coudn't be hit anymore
which  would subsequently reduce the number of boxes during tracing.
There were 138 times more objects (138837%)  in the second case but tracing
time increased only by 48%. 48% sounds a lot but the number of objects for a
complete fern (not only a wing) with auto LOD will have approx. 8000
objects!
I am shure that the single-mesh-solution has some advantages in case of a
complete fern since the bounding boxes are spread over the entire picture.

Anyway, the difference is (up to now) only 30 seconds. I decided to leave
the code as it is since I have to concentrate on the shape of the wings and
a macro assembling a whole fern. If parsing time gets more and more an issue
I can flip over to the single-mesh variant.
Thanks for your explanations,

best regards
SY

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