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View Full Version : Multiple Rail Extrude: test LWO attached



jeric_synergy
05-09-2014, 01:46 AM
Is there some reason this object won't multiple rail extrude??

Thanks!

121824

prometheus
05-09-2014, 02:32 AM
You canīt rail extrude a spline..even less two splines.

Think You are approaching it the wrong way.

you can rail extrude along a spline, but you need to select polys from another object segment to do that.

JoePoe
05-09-2014, 09:18 AM
....you can rail extrude along a spline, but you need to select polys from another object segment to do that.

He's got it set up okay (almost).... two splines in one layer and a disc in another.

Jeric,
you just need to separate the ends of the splines a tad.

this is what I get 121831

This is what I think(?) you want..... 121832

I shrunk the disc down so the diameter was the same distance as the gap at the start of the splines.

jeric_synergy
05-09-2014, 09:28 AM
JoePoe, #1 is very close to what I'm desiring. Thanks so much! I was actually hoping to WELD the two ends so that the extrusion tapered down to zero, but I guess I'll have to fudge that bit. (And, logically, I don't know how the software would know this without being telepathic.)

SO, there must be critical threshold over which a polygon that exceeds the opening in a multiple rail setup fails. Some tedious experimentation would establish what that is, I guess.

Prometheus, IIRC (#awayFromLW) there's a poly in layer 1, and 2 splines in layer 2: isn't that the correct setup for a multiple rail extrude?

JoePoe
05-09-2014, 10:15 AM
No problem.
I'm not sure whether it's a function of the poly exceeding the opening (although I can see getting into trouble with extremes, so I do see your point)..... or just that the spline start/end points can't be coincident.

Here it is with very little manipulation to the ends of the splines AND tapering to 0.... shrunk the post-extrude ends with "H" to almost nothing (and made them SubD friendly).
An intriguing shape in the end (I can't put my finger on why,.... or maybe it's because I want to put my finger on it :dance: :D)

121833

jeric_synergy
05-09-2014, 11:09 AM
By "coincident" in this specific context, do you mean each of the several splines in a multiple spline extrusion MUST have unshared endpoints? Unshared AND non-coincident? (IIRC, #awayFromLW, I unwelded the endpoints of the splines, but didn't move them.) --It would be very elegant if one COULD use multiple splines with welded endpoints.

re last paragraph: LOL!!! Well, the actual shape I'm envisioning is a pretty classic "toothpaste on brush" shape, so maybe it'll be a bit more mundane when I'm finished. ;)

JoePoe
05-09-2014, 11:48 AM
That would be the breast...... sorry, I mean the breast....... :foreheads :bangwall:....BEST toothpaste ever!!


By "coincident" in this specific context, do you mean each of the several splines in a multiple spline extrusion MUST have unshared endpoints? Unshared AND non-coincident? (IIRC, #awayFromLW, I unwelded the endpoints of the splines, but didn't move them.)

afaik, yes.

jeric_synergy
05-09-2014, 12:26 PM
Ha. :D

Anyway, I used to use "Align to Rail" to line up SINGLE Rail Extrusions... here I just eyeballed it. While I could always use AtoR after hiding all the secondary rails (or whatev), is there any consarn newfangled way to do so?

Ideally, "Chose Primary Rail, Invoke Script, and poly(s) in Background Layer are aligned, and then fore/backgrounds are swapped" would be the least mouseclicks.

After separating rails and resizing poly, here's my first try, quite close to desired shape, VERY obliged JoePoe!!! Mucho gracias!

121834

JoePoe
05-09-2014, 12:51 PM
lookin' good :thumbsup:

AtoR works with multiple rails. Even gives you the option to align to the primary or to center amongst many.

121835

prometheus
05-09-2014, 04:31 PM
JoePoe, #1 is very close to what I'm desiring. Thanks so much! I was actually hoping to WELD the two ends so that the extrusion tapered down to zero, but I guess I'll have to fudge that bit. (And, logically, I don't know how the software would know this without being telepathic.)

SO, there must be critical threshold over which a polygon that exceeds the opening in a multiple rail setup fails. Some tedious experimentation would establish what that is, I guess.

Prometheus, IIRC (#awayFromLW) there's a poly in layer 1, and 2 splines in layer 2: isn't that the correct setup for a multiple rail extrude?

Iīm sorry, I thought I checked that layer and found no geometry at all in that layer..I should have gone to bed:D

havenīt checked upon the rest and how you solved it etc, might take a look at that, but it seems you got that covered from others etc.

regarding lofting...or similar, but I reckon you might now about this tool...Cm_loft works on splineīs And polyīs with the same point amount that is, and works only in 32 bit lightwave versions I think.
Itīs no extrude along a spline..rather lofting with the splines as cross sections.
https://www.lightwave3d.com/assets/plugins/entry/cm_loft/

I think itīs a great lofting tool, wish we could see such things interactive and perhaps with a stack so you can go back and change cross section/lofting curves as you see fit, and have the lofted mesh update in realtime.
I will look forward to what victor can implement with his development on the new "nurbs" surfaces for lightwave in lw cad for the next version.