pouët.net

I thought about this, and I wanted to take it from the point of view of someone writing a 3D modelling program - how is a scene stored? If I wanted to store it, would I just store the vertex data for each polygon (ignoring things like "undo" and all the program specific stuff), or something a bit, well, cooler? :) Are there any pointers on the web for something like this?

Thanks.

depends on the fileformat. http://en.wikipedia.org/wiki/List_of_file_formats#3D_graphics help yourself.

if you want to store 'stages' you might wanna look into procedural modelling, as for example in werkkzeug and stuff. basically then you need to store a selection of vertices or polys and which operators/modifiers/however you wanna call them + manipulation values

make your own fileformat !!

maybe have a look at the autodesk fbx sdk, which is a sdk used by many 3d software packages.
its a data exchange format and can also be used as to build and animate complete 3d scenes...
http://www.autodesk.com/products/fbx/overview
also maybe look at 3ds max sdk api ;)

collada ftw. ;)

In a file or in memory?

3dsmax stores the modifier stack, so you've got a list of operations which create the final mesh.
This way you can (with certain limitations) still go back and change fundamental parameters at the beginning of your work.
It doesn't really make sense to store just the final polygons as it makes later modifications pretty hard - that's like photoshop wasn't able to save its' layers...