RSX Secrets

[joker454]

Err, the backface cull removes 50% of faces, by definition.

It depends on the polygon distribution of the model in question. For example, on a human head there are more verts in the face area to model areas like the nose, eye socket, mouth, etc. So if your camera was looking at the face when you backface culled it, you would not be removing 50% of the faces. Alternatively, if you know your game camera is bound to certain restrictions, you can both pre backface cull models to a certain extent at the art level, or purposely spend less of your vert budget on certain parts of the model. In cases like that you will also get less than 50% cull from backface culling.

 

[psorcerer]

It depends on the polygon distribution of the model in question. For example, on a human head there are more verts in the face area to model areas like the nose, eye socket, mouth, etc. So if your camera was looking at the face when you backface culled it, you would not be removing 50% of the faces. Alternatively, if you know your game camera is bound to certain restrictions, you can both pre backface cull models to a certain extent at the art level, or purposely spend less of your vert budget on certain parts of the model. In cases like that you will also get less than 50% cull from backface culling.

If all your models are convex and you have millions of triangles it's statistically correct to say that it will be very close to 50%.
All other cases are either pre-optimized or not common enough.

 

[PellePlutt]

If all your models are convex and you have millions of triangles it's statistically correct to say that it will be very close to 50%.
All other cases are either pre-optimized or not common enough.

I think it's fair to say that things like terrain or billboards might significantly reduce that in lots of applications...

 

[kumayu]

Depends on game type....
50% Backface culling is rare in some game.
Most games limit your camera path.
In a car racinng game , your camera alway above or after the car.
A building sits beside the road could pre-discard all back faces by artist
, since you can't reach the back side ,why keep it?
Most stastic objects can be culled by a talented artist.

The terrain or billboards(no back side) , the tree(two side display)
The particle effect........ there are many polygons never need culling.....

I think 30% culling is more possible figure.

 

[archangelmorph]

Depends on game type....
50% Backface culling is rare in some game.
Most games limit your camera path.
In a car racinng game , your camera alway above or after the car.
A building sits beside the road could pre-discard all back faces by artist
, since you can't reach the back side ,why keep it?
Most stastic objects can be culled by a talented artist.

The terrain or billboards(no back side) , the tree(two side display)
The particle effect........ there are many polygons never need culling.....

I think 30% culling is more possible figure.

There is no figure..

It's really a scale which slides backwards and forwards depending on the environment (+ type of), entities within the env (density, capacity + type of) & the direction of the camera from frame to frame..