Topic: backface culling (Read 4203 times)

psikotropico · « **on:** September 25, 2009, 06:25:04 AM »

hi...

What about backface culling option in SkinMesh object? Could be possible to implement this feature?

With backface culling option, we would need less polys to implement transparencies... now I must duplicate transparent polys... it's a pain in the ass (

)... with foliage and trees over all... and I can't get total transparency... always there is some polys that break other polys... (see attached picture)

thanks

3D Rad Developer - Fernando · « **Reply #1 on:** September 25, 2009, 06:55:03 AM »

I think backface culling is when the engine automatically avoids processing polygons (triangles) that face away from the camera. This is something that 3drad already does.

The problem you mentioned is caused by surface sorting (certain surfaces are rendered before others, thus creating issus with transparency). This is a limitation of realtime rendering in general and there is no easy solution.

3D Rad provides various features to help you minimize the problem thoug (see for example transparency sorting setting in SkinMesh help file).

For a discussion about these issues, please see

http://www.3drad.com/forum/index.php?topic=1123.0

psikotropico · « **Reply #2 on:** September 25, 2009, 08:54:22 AM »

ok... what means "surface sorting"? how can I sort the surfaces? I don't understand the concept..

I've read the post you mentioned, so I have another question: What's the better way to fill a landscape with trees and foliage? Using individual tree objects or making a whole skinmesh with all plants? How can I get better performance?

I'm talking about 500 palms and trees and 500 bushes... more or less... each palm have 126 polys and each bush have 15-30 polys... total polys:

78.000 polys... I don't know if those are too much polys...

thanks!

EDIT: Finally solved! (see attached picture) I will make a whole tree object with all plants inside (I don't want 500 objects in the object list window

).

Sharp911 · « **Reply #3 on:** September 25, 2009, 10:32:15 AM »

use imposters for your trees and bushes. That way you only got 1 object of each skinmesh model you want to use

psikotropico · « **Reply #4 on:** September 25, 2009, 10:46:45 AM »

hi sharp... sincerely i hate imposters...

I can't control them, even there are some resources like imposter grid that can help to place them accurately... but If i use skinmeshes i will have troubles with transparencies again... tree objects works fine with transparent meshes, I don't know the limit though...

for now works fine

Sharp911 · « **Reply #5 on:** September 25, 2009, 12:16:07 PM »

Yeah I dont like them either

but they are a big help once you figure out how to place them

psikotropico · « **Reply #6 on:** September 25, 2009, 12:34:16 PM »

work in progress... all palms are only one tree object... all bushes are another tree object... for now runs without slowdown...

let's see the limit!!!

Sharp911 · « **Reply #7 on:** September 25, 2009, 01:45:35 PM »

Looks great ^^

loop · « **Reply #8 on:** September 25, 2009, 04:26:46 PM »

YEAH! it looks great!
I like the style in tha last picture

shadmar · « **Reply #9 on:** September 26, 2009, 06:21:29 AM »

Great looking scene indeed

3D Rad Developer - Fernando · « **Reply #10 on:** September 26, 2009, 11:40:59 AM »

Imposters are perfect for the purpose, extremely fast and very flexible. However if you can put all the trees in one single .x file, perhaps using one single texture for the whole model, it will be even faster to render.

loop · « **Reply #11 on:** September 27, 2009, 04:56:51 PM »

Quote from: 3D Rad Developer - Fernando on September 26, 2009, 11:40:59 AM

However if you can put all the trees in one single .x file, perhaps using one single texture for the whole model, it will be even faster to render.

interesting ...

so, it dosnt matter if the .x file that contains the trees is huge and the skinmesh have zillions of triangles as far there's a single texture??

what about loading times?

Im about plant vegetation and other details that repeat them self in my game and was preparing to deal with imposters, but you are saying that if I make a single huge model with a single texture... that gonna give me even better perfomance results than imposters??

Dart · « **Reply #12 on:** September 27, 2009, 05:22:27 PM »

im really not sure about that one, but i'd go with the giant skinmesh(as you can create a second copy for a rigidbody) or imposters if it happens to be easier.

another thought is it's the same rendering as imposters, except more polies are loaded into the ram at start

3D Rad Developer - Fernando · « **Reply #13 on:** September 28, 2009, 03:34:28 AM »

Unless you intend to hide/show imposters based on camera distance or use imposter flexibility to cull trees that you don't need to render to improve performance, the unique .x file solution will be faster.

However, if you have a billin polygons in them, it may not be that fast to render I fear

But so many trees would also be slow as imposters though, unles, as said, you use some culling method.

psikotropico · « **Reply #14 on:** September 28, 2009, 10:30:06 AM »

thanks guys for the comments...

I've attached some shots... 250 palms = about 40.000 polys... one single tree object, but still having troubles with sorting... why? is this a bug? why only in certain places?

the system is going down a bit, but it's not optimized yet...

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Author Topic: backface culling (Read 4203 times)

psikotropico

3D Rad Developer - Fernando

psikotropico

Sharp911

psikotropico

Sharp911

psikotropico

Sharp911

loop

shadmar

3D Rad Developer - Fernando

loop

Dart

3D Rad Developer - Fernando

psikotropico