Subdivision surfaces

[Tobias]

Hi, been lurking for a while. Thought I'd give something back that you might find mildly amusing if not useful.

Subdivision surfaces implementation (the Butterfly scheme) that can handle any mesh with triangular faces you throw at it (open as well as closed). Simple to use as well:

Code:

TriMesh mesh = {some trimesh};
Subdivision subdivision = new SubdivisionButterfly(mesh.getBatch(0)); // prepare for subdivision
subdivision.subdivide(); // subdivide
subdivision.apply(); // Applies the new subdivided buffers to the batch
subdivision.computeNormals(); // calculate new normals

Star:



Pyramids:



Disc:



It interpolates any buffer you'd like it to (that would probably mostly be vertex buffer, color buffer and texture buffers, but I guess you could feed it an alphamap as well)

Get it here: http://bokbloggen.com/stuff/subdivision.zip

The test program subdivides every time you press 'Z', a couple of different shapes are provided. Press 'T' as usual to take a look at the magic in wireframe mode.

Take a look at the code and feel free to suggest improvements. Mostly looking for a better way to make it fit with the structure of jME (extending TriangleBatch, perhaps?). I haven't worked too much with jME yet, so I feel like this might not be the best way.

Papers I used during development are stated in the source, interesting stuff but highly confusing

[renanse]

Very cool!

[nymon]

Thats neat. 

[sfera]

looks very nice

[MrCoder]

great! lets look this through and get ready for jme inclusion...i'll see if i can find the time tonight...

PS. hur kommer det sig att en bokrecensent pillar med jme? DS

[Tobias]

I'm glad you guys like it. Forgot to mention that it currently does not handle triangle strips or fans, only three indices per triangle.

PS. Jag vill bli indiespelsutvecklare DS.

[12]

Tops man that is really cool!!!!
                 Thanks
                      12

[12]

Any body have any luck with an obj for example, excuse my ignorance. What kinds of models can I try if any
            Thanks    12

[sfera]

subdividing models is tricky because you usually want to keep some of the (hard) edges. such things are best done in a dedicated 3d modelling program.

but if you just have some simple models (and are sure you want to do this), you just load them, walk the loaded tree, grab the trimeshes and apply the subdivision to them as described in tobias's post.

[12]

Hi Sfera, I just wanted to try it on an organic shape which should be fine but how do I walk the tree...gulp sorry for my poor knowledge, I'm new but keen   can you load .objs directly or do you have to change some thing
       Thanks 12

[sfera]

take a look at the source of TestObjJmeWrite to see how to load a .obj file. after loading it, you get a Savable from the BinaryImporter. that Savable is a SceneElement. then you can test with instanceof (or getType()) what kind of SceneElement you are dealing with. if it's a Trimesh you just apply the subdivision, if it's a Node, you grab the children of the node and test them the same way you tested before.

[renanse]

PS: this is in cvs

[Tags:]

jMonkey Forum > Community Activities > User Code & Projects (Moderators: Outrunner, erlend_sh, Momoko_Fan, Vardamir, .:emp...imm0|82:.) > Topic: Subdivision surfaces