OpenCTM format

mLink

http://openctm.sourceforge.net/?page=about

I saw the latest beta version of xnormal supports this format, and checking out their site, it seems to be great. It's able to compress the file size of your meshes in a lossless way, or lossy if you want an even smaller file.

What do you guys think of it?


*oops, this probably belongs in the Technical talk section.

oXYnary

Would that bring an overhead when starting the game to uncompress the objects for viewing?

mLink

From what I understand of it, there are 3 different ways you can convert the file.
Raw, M1, and M2. Raw shouldn't cause any overhead because it doesn't actually compress the files, the other two ways might, since they actually compress the data somehow.

I still can't figure out how to get this thing working, the documentation is a bit confusing, and at the moment, seems to be written for programmers to understand.

jogshy

The OpenCTM has three types of compression, basically:
1. Lossless compressing the data as 7zip does ( RAW )
2. Lossless re-scaling the mesh internally to fit better the 7zip's compression algorithm's quantization ( MG1 )
3. Lossy using fixed point maths ( you'll just loose a bit of quality in the decimals ). MG2

The OpenCTM package adds a 3D viewer which can re-save the meshes to CTM format using a button ( it will use the #1 or #2 compression type probably, I'm not sure ).

It also adds a command line ctmconv.exe tool to convert OBJ/LWO/COLLADA/etc meshes into the CTM format letting you to set more advanced options ( like the decimals precision ).

I just usually load the mesh I want to compress into the OpenCTM's viewer... and press the save button.

Here is a video I foundhttp://www.vimeo.com/8997283