Hi again,
So I've been able to at least partially implement some suggestions that
I was given in the previous posts by Tim and Robert. Here are some
results in before-after style.
Scene stats haven't changed significantly.
Camera stats: Before After
State graphs 1254 846
Drawables 2117 1669
Vertices 485531 368844
PrimitiveSets 4899 1694
Triangles 17122 161448
Tri. Strips 191 32
Tri. Fans 7212 36
Quads 106464 9578
Quad Strips 534 356
Total primitives 131523 171450
Vertices per pset 99.1 217.7
This was achieved by doing 2 things:
* Uniformizing even more state, even if it leads to graphical artifacts
(our artist can go in and fix those later), for instance cull face
settings. This made texture atlas generation more effective which
lowered number of state sets / state graphs.
* Backporting the INDEX_MESH, VERTEX_PRETRANSFORM and
VERTEX_POSTTRANSFORM optimizers into my optimization tool which uses OSG
2.8.3. This lowered the number of PrimitiveSets by combining and
converting primitive sets to all use indexed triangle lists.
However, in our simulator itself as well as when testing with a dumped
scene in the osgshadow example, even though these numbers are lower,
they did not result in a large cull/draw time reduction, and so the
frame rate is still largely the same (improved from ~35 to ~40 fps). So
I guess even though I more than doubled the number of vertices per
primitiveset, the numbers (state graphs and primitive sets) are still
much too high.
My next step is eliminating textures that repeat, to even further
improve texture atlas generation. This will again lead to some graphical
artifacts unfortunately...
I did the test of removing almost all statesets after scene load. The
result was that most of the time, the frame rate was close to or at 60.
In the worst case scenario (whole scene visible, which is also what I'm
giving you stats for since the beginning) it went to about 50 fps in our
simulator, so it's not just statesets that are a problem. I think I
really need to lower statesets and primitivesets in combination to be
able to get good results.
I'll also look at decreasing the cull time, since in practice that
should pay off in double (because of the shadow pass) and even quadruple
or more sometimes (ocean can have reflection turned on, for now we've
turned it off; also we often have extra picture-in-picture view(s) to
render in addition to the main view).
Any further comments would be appreciated. Also any suggestions as to
what else I can do would be appreciated as well. At least I'm starting
to see some results, which is encouraging since up until now nothing I
had done had had a significant effect (I was scrounging 1 fps here, 0.5
fps there...).
Thanks in advance,
J-S
--
______________________________________________________
Jean-Sebastien Guay [email protected]
http://www.cm-labs.com/
http://whitestar02.webhop.org/
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