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View Full Version : Multiple Different Cross Sections??



hillborne
06-21-2004, 02:08 PM
Hello LW friends.

My dilemma is dealing with extruding items with different and sometimes complex cross sections. Sometimes it is a simple rounded box cross section transitioning into a circle but other times it's a pointed hexagon to a circle and back to a hex.
I've done it in the past (see image) but had to resort to multiple messy skin operations and hand-tweaking to get the right shape. If there is a change I have to start from scratch and that is quite a pain.
I know in other modeling packages you can do this relatively easily but I can't figure out the easiest method in LW.
Thank you all for your time and consideration and hopefully your help.

Gordonpee
06-21-2004, 08:59 PM
Hilborne,

It looks like you would be able to do these easily with Splines.
Isn't that how you built the piece shown?

Gordon

hillborne
06-21-2004, 10:42 PM
No, I didn't use splines. I had it morph from one cross-section to another several times then I had to manually move and scale the the blended cross sections. It was a pain and much harder to get the right flow.

How would you go about using splines? How many splines would it take to make what I did? What if I wanted to change cross sections? Would I have to remake the splines?

Is there a way to have your different cross sections in one window and the rail in the back and they blend together?

Thanks!

toonafish
06-22-2004, 06:51 AM
Check this page http://www.m2estudios.com/plugins.html it has a lot of free spline loft plugins that will help you out. There's even a loft tool with bezier interpolation that allows you to use splines with different point count.
So just create you cross sections with splines, use the loft tool and you're done.

I replaced Lightwave's own loft with this one, it's much better.

Fish
http://www.toonafish.nl

hillborne
06-22-2004, 09:54 AM
Thanks for the reply! So I'm assuming there isn't a 2 step operation built into lightwave where you create your cross sections (with different point counts,order) then create your rail and they are blended together?

Toonafish: That seems to be helpful. Do you know exactly which plugin it is? There are a couple on his site and it's a little confusing. I want the one where you can loft splines with different point counts.

koop
06-22-2004, 11:16 AM
You can use the skin command for that.

the cross sections don't have to have the same amount of vertices.

hillborne
06-22-2004, 10:53 PM
Yeah, I used skin to make that image but skin does not take into account a guide rail in the background...it's just a simple A to B solution.

If you want to use skin you have to create a whole bunch of different cross sections, which is basically what 'morph' does and then manually move and scale the cross sections.

/sigh...