View Full Version : How are modeler splines implemented?

08-29-2003, 03:14 AM
I'm planning a LScript dealing curves, but I don't know how modeler splines are implemented.

I need to obtain certain information from the curve, such as derivates, positions, lengths, etc. As far as I've read, there's not any command doing so, so I supose you have to manually obtain the curve parametric equations (matrices) from the interpolated points

In this case, what are suposed to be modeler curves? I supose they are cubic splines, but I can't figure how are derivates in the first and last points assigned. (They are not obtained from the segment connecting the first and secon point, and user can't control them, so they have to be obtained from point data in a certain way I can't guess).

Moreover, obtaining splines matrices for each segment can be a lot of work (involving inverting matrices and so on). There's not any information about this? If modeler can draw curves (and so it calculates all this) would have to be a way of getting this information!

Bye, I hope anyone could help me.

P.D: I've yet finished an interesting plugin wich BEVELS MULTIPLE POLYS (if I don't mistake is the first free tool in doing so!) and has several options (such as circular and shaped bevels, all in a fake modal interactive tool). I will post it soon, it has been a bit of work, but the result is really good.

08-29-2003, 05:27 AM
Can't help you, but that bevel tool sounds cool :)

08-29-2003, 05:49 AM
David Ikeda's SuperShift (included in DI PowerTools) can bevel multiple polys and it's free.


Having choice can't be bad tho and your plugins sound like it will have extra options, tell me if you are looking for a tester :D

08-29-2003, 05:59 AM

That's the most thourough discussion on Modelers splines I've found. I wanted to make a splinecutter aswell as a drilltool for splines (http://w1.851.telia.com/~u85113006/temporary/createIntersection.jpg) myself (a tool that could intersect and add a point to a spline at a given X Y or Z value), but only got as far as getting myself a general understanding how these matrices work. Not being a programmer nor a math genius I guess I sort of choose to leave it hanging until my skills in both fields improved.

I wish you the best of luck and complete success! :)