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optimal polys count

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Hi I have a scene: terrain and some(about 30) trees(each made of 4 sprites and a torus) and some other objects. If I move camera to see all trees(textures are in tga format and have alpha transparency), I get about 30 FPS. If I render all objects without textures, I get about 500 FPS. My PC specs:850MHz, 256MB, GF2 GTS. I think the fps depends more on textures size than on polygon count. I don''t know what is the most optimal polys count/textures size combination. What do you think about it

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you might encounter one of following problems:
1.your texture sizes are too big. like if you use some 1024x1024x32bpp(one bitmap takes 4mb of ram!) textures you trash your ge2 memory and it needs to get textures from system memory all the time which hits badly overall performace(to solve it simple try using smaller textures resolution and/or use only one-two textures on all trees instead different texture per tree)
2.you reach fillrate of your geforce2 - your polys are way too big and make your geforce card scream. It happens often if you have several/some polys that take whole/a lot of screen space. Speed difference described by you is quite enormous thru, so fillrate problem might be only a part of your problem.
3.drivers bug, don''t think so thru if neither of the above stuff helps, you might try installing different drivers and check their results.
hope it helps

With best regards,
Mirek Czerwiñski
http://kris.top.pl/~kherin/

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Dunno if this is the case, but another possible reason is you are not filtering out uneeded set texture operations. ie

SetTexture( LPDIRECT3DTEXTURE8 NewTex )
{
static LPDIRECT3DTEXTURE8 OldTex=0;
if( OldTex == NewTex ) return;
else
DXDisplay->SetTexture( Layer, NewTex );

OldTex = NewTex;
}

[The views stated herein do not necessarily represent the view of the company Eurocom ]

Eurocom Entertainment Software
www.Eurocom.co.uk

The Jackal

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Hi !

1) Sort your polygons by the used texture to minimize texture-switches, since they're quite slow.
2) The number of polys does not really matter in this case. On GF3 for example, the triangle-size for optimally using the rendering-pipeline is 12 pixels. For example, if you want to draw a background-image onto the screen, it does not make a performance difference whether you use 2 big triangles or 200 small ones.
3) Use big vertex buffers, you cannot get good performance when using lots of small ones.

cu

Edited by - nufan on November 1, 2001 6:12:09 PM

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