Hello all. I have a number of questions for you all.
World Description:
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My project consists of creating a virtual world. My test world is
4000x4000 world units. This is broken up into a large 40x40 grid, for a
total of 1,600 cells. Each cell in the grid is a mesh 50 triangles in it,
covering 100x100 world units each. My textures 512x512 and mapped into each
mesh 1:1, meaning each texture is mapped into the 100x100 world units. This
allows me to handle changes in terrain, add paths, roads and other things by
playing with the textures.
So with everything loaded up I have 80,000 triangles being rendered
in 1,600 seperate meshes. The average tree has an additional 36 triangles
each, and there is 500 trees in this area, for an additional 18,000
triangles.
Current performance is as follows:
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1: clipping at about 50 percent of world : 18 fps
2: clipping at about 20 percent of world : 18 fps
3: clipping at about 10 percent of world : 18 fps
4: no clipping, 100 percent of world : 8-12 fps
I have played with a bunch of things, for clipping of 50 percent of
world and under, there is nothing that will improve the 18 fps. Its as if
Java3d has decided that is fast enough and doesn't bother rendering more
frames than that. In other words, it seems to be a soft limit.
I was quite pleased to see the 8-12 fps with no clipping at 100,000
texture mapped triangles. I can move around although it is sluggish. I
would like to try to improve that though. I like the smoothness of my
terrain and don't want to give up that quality, but would like to move the
clipping back a bit and still get good performance.
Some ideas for improvement:
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If I break my world into a grid hierarchy, so like a 8x8 grid, each
one having 5x5 cells in it, could I LOD the big cell and put a single
decimated mesh for long distance viewing? In other words, at a far distance
the grid of 8x8 subgrids of 50 triangles (3200) could be replaced with a
mesh much smaller, maybe 1/8th the number of triangles?
Q:Would this work well?
Q:Should I texture map this LOD mesh with the same texture, or come
up with a representative color and solid map it?
LODing trees
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My trees are built as follows:
1.Trunk is 3, 6 sided cylinders, standing end on end each tapering
to the top. This is built with 24 triangles.
2. The branches are two transparent planes, each with a transparent
GIF blended on it. Thats another 4 triangles.
I don't know the relative cost of the transparent parts, but I could
create a decimated version for LOD, I could use a 4 sided pyramid (4
triangles) for the trunk, and use a 4 sided pyramid for the branches, This
would be a total of 8 triangles and would have no transparent parts.
Q:is this a good approach?
Performance
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I am using, I think its called retained mode, where Java3d is
handling the rendering cycle. I would like to keep with that because I like
the architecture.
Q: What kind of FPS should I be seeing?
Q: Am I maxing out at 18 fps because I don't have anything in the
scene moving faster than that? I have no interpolators going, no timed
behaviors except my keyboard.
Q: If I want to do an animation like rotate a transparent GIF over a
transparent cylinder (for a fire effect), how many FPS do I need for it to
look realistic?
Thanks in advance, I will attach a screenshot to help you visualize
what I am doing.
Dave Yazel
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