BigShooter

08-05-2003, 10:20 PM

I've tried to experiment with some OpenGl interactive modeling, but I have no idea how to do it and I can't find any examples of that... I'l really appreciate any help you guys can offer me on this one. This is what I'd like to do:

Imagine starting up with a simple polygon cube. I would like the used to be able to click on one of the points of the cube and then "+" would bevel this point (that is the point would be turned into a triangle on the corner of the cube...) I don't even know how to approach this... here are some of my problems:

- how do I do the selection? It seems that the selection buffer only works for objects, not components...

- if I store the geometry in polygons (4 vertices per poly) then beveling one point will create 3 sides that have 5 points, not 4

- finally, the hardest part... how do I update the array of vertices? I mean this is hard for even a cube, but if I have say more complex object whose vertices are stored in an array, then how do I know which point in the array was picked... how do I now add the extra 2 points created, so the sctructure of the object would still be valid (e.g. indives kept intact, if used)?

I know this question is huge and I really appreciate any help. It would really make me feel that I'm getting good with OpenGL :-)

Finally, I'm still looking for some good point-beveling algorithms...

As always, huge thanks,

Luke

Imagine starting up with a simple polygon cube. I would like the used to be able to click on one of the points of the cube and then "+" would bevel this point (that is the point would be turned into a triangle on the corner of the cube...) I don't even know how to approach this... here are some of my problems:

- how do I do the selection? It seems that the selection buffer only works for objects, not components...

- if I store the geometry in polygons (4 vertices per poly) then beveling one point will create 3 sides that have 5 points, not 4

- finally, the hardest part... how do I update the array of vertices? I mean this is hard for even a cube, but if I have say more complex object whose vertices are stored in an array, then how do I know which point in the array was picked... how do I now add the extra 2 points created, so the sctructure of the object would still be valid (e.g. indives kept intact, if used)?

I know this question is huge and I really appreciate any help. It would really make me feel that I'm getting good with OpenGL :-)

Finally, I'm still looking for some good point-beveling algorithms...

As always, huge thanks,

Luke