PDA

View Full Version : 3DS, mesh and ROCK'N'ROLL!



white skies
04-17-2005, 08:49 AM
Hi!
This time i have two questions:

1. Is 3ds a good format in order to create 3d models?
2. Is there a better way then using glEvalMesh and his friends in order to draw 3d models?
thanx :D

SirKnight
04-17-2005, 11:37 AM
1. Is 3ds a good format in order to create 3d models?
If the 3ds format does what you need for your particular program then YES!



2. Is there a better way then using glEvalMesh and his friends in order to draw 3d models?
Use vertex arrays? You know...like glDrawElements and whatnot.

-SirKnight

fpo
04-18-2005, 05:45 AM
The bad thing about the 3ds file format is that it does not include vertex normals. So you have to compute vertex normals after loading the model from disk.

But as the 3ds format only supports one texture coordinate per vertex, you will not be able to compute vertex normals correctly. Vertices where texture mapping is discontinnuous will be splitted when saving the 3ds file and this means normals will also be discontinuous at that vertices (for example in a sphere you will get a hard edge where the texture map join sides).

white skies
04-18-2005, 07:47 AM
Ok!
Thanks to both of you! :)

zed
04-18-2005, 10:16 AM
IIRC 3ds doesnt handle any sort of animation as well (its an old format, hmmm no normals sounds crazy)
youll find unlike image files since ppl needs a varied most ppl write there own format

ToolTech
04-19-2005, 12:25 PM
Just some comments..

1. 3ds has keyframe animations. You can easily add skinning to this to get good animations.

2. 3ds has a hierarchical structure so therfore you can use it to control hierarchical transforms.

3. 3ds has smoothing groups. These can be used to group vertices and "smooth" a normal over these vertices. You can get a perfect smooth sphere by using this.

There are some bad limitations. You can only get 8 chars in the names so therefor it is difficult to use name encoding for specific stuff without an external reference file.

It is also bad that 3ds only have one texture coord per vertice. This can be handled by the texture baking feature but in general it only leads to overflow of textures...

white skies
04-20-2005, 08:08 AM
Ok! thanks to you all! :)
I'll probably use my own format...

knackered
04-20-2005, 08:46 AM
You could try the X file format:-
Recent article on loading them without using DirectX:-
http://www.gamedev.net/reference/programming/features/xfilepc/
It's a good format.