OBJ file's strange render effect

ym1218 · Post by **ym1218** » Sat Jul 04, 2009 11:21 am

I don't know why got this effect, someone can give me some advices? thanks

ym1218 · Post by **ym1218** » Sat Jul 04, 2009 11:36 am

Here is another snapshot.

BlindSide · Post by **BlindSide** » Sat Jul 04, 2009 3:23 pm

If you can provide us with a model that demonstrates this problem it would help.

Does this always happen or only from certain angles. Does it happen with all material types?

If it's a problem with Irrlicht than I may move this to the bug forum.

hybrid · Post by **hybrid** » Sat Jul 04, 2009 9:14 pm

I guess it's simply too high poly count. The second half of the tris is simply discarded due too an overflow in the indices. You have to introduce groups in you rmesh to get below the 65535 faces per meshbuffer count.

ym1218 · Post by **ym1218** » Sun Jul 05, 2009 12:03 am

Thank you hybrid, I think you are right, there is a meshbuffer more 65535 faces in this model.

I want to modify Irrlicht to support more faces, what do you think about it?

Here is my model files
http://www.soft5a.com/ym/files/sofa.zip

hybrid wrote:I guess it's simply too high poly count. The second half of the tris is simply discarded due too an overflow in the indices. You have to introduce groups in you rmesh to get below the 65535 faces per meshbuffer count.

bitplane · Post by **bitplane** » Sun Jul 05, 2009 12:26 am

Sounds good. You have two options-

1) Make the OBJ loader split the mesh into more buffers

or

2) Switch to 32-bit indices if there are over 65536 vertices. Look at the PLY loader in SVN trunk for an example.

ym1218 · Post by **ym1218** » Sun Jul 05, 2009 1:01 am

Thank you Bitplane, I'll read PLY loader now.

bitplane wrote:Sounds good. You have two options-

1) Make the OBJ loader split the mesh into more buffers

or

2) Switch to 32-bit indices if there are over 65536 vertices. Look at the PLY loader in SVN trunk for an example.

hybrid · Post by **hybrid** » Sun Jul 05, 2009 10:18 am

Since so large mesh buffers can give render problems on some older machines, and will negatively impact the render performance in general, it's usually wise to keep groups in the object file. Those will automatically create meshbuffers for each of them, and hence giving properly divided meshes. Auto-splitting is usually giving seams in the objects, due to vertex duplication at the borders.