Extrude along spline

Forums Technical Discussion Extrude along spline

32669 25 3


nandez83: Member; 6 posts; Joined: April 2009; Offline

May 6, 2009 7:25 p.m.

Hi guys, i have a simple question.
In Houdini is possible extrude a polygon along a spline.
Extrude or PolyExtrude don't have this option…
Excuse this noob question!!
TNX.
:wink:


pbowmar: Member; 7025 posts; Joined: July 2005; Offline

May 7, 2009 12:05 a.m.

Sweep SOP is a good place to start…


flyingc: Member; 160 posts; Joined:; Offline

May 7, 2009 1:28 a.m.

pbowmar
Sweep SOP is a good place to start…

but how to align the curve to the center of a polygon?


nandez83: Member; 6 posts; Joined: April 2009; Offline

May 7, 2009 3:34 a.m.

Ok, i create a polygon mesh (cube)
In mode “create in context”, I add a curve.
With the face selected i load sweep from TAB menu
Next step i select the curve and i press enter.
The result is a “N” number of cube along my spline, But nothing extrusion.
After this i tried to use skin operetor…But….Nothing

TNX for help and support!
GNS71


xtimmyx: Member; 166 posts; Joined: Oct. 2008; Offline

May 7, 2009 4:36 a.m.

Try sweeping a profile curve instead, shaped like a square. I don't know if face extrusion along curve is possible in Houdini, but I'm not saying it's not.

Attachments:
sweepExample.hip (37.3 KB)


Simon: Member; 2199 posts; Joined: July 2005; Online

May 7, 2009 4:38 a.m.

Its a function that is missing from houdini.

At the moment you have to build your own.
In your example you'd need to first extract the face you wish to extrude - using a blast sop, then align it to the origin (with its local up axis aligned to the world z axis) and then sweep it along your path and skin it. Finally merge the result back with the original minus the face you have swept. The tricky bit is getting the swept face to match exactly with the face that was removed but for a box you should be ok.

If you do this a lot you'd need to wrap it all up in an otl, or pester Sesi to add it as an option to the poly extrude node.

The trick is finding just the right hammer for every screw


nandez83: Member; 6 posts; Joined: April 2009; Offline

May 7, 2009 6:21 a.m.

Hi guys, I can extrude along spline with use this network!
It's little bit complicated for the first time, but now with exercise i'm a king of extrusion!

tnx gns71

Attachments:
ext_along_spline_.hip (46.9 KB)


flyingc: Member; 160 posts; Joined:; Offline

May 7, 2009 9:41 a.m.

Simon
….
In your example you'd need to first extract the face you wish to extrude - using a blast sop, then align it to the origin (with its local up axis aligned to the world z axis)

if use Sop ,how to align the face to the origin? I want to make a digitalasset.


Simon: Member; 2199 posts; Joined: July 2005; Online

May 7, 2009 4:07 p.m.

Well…… the way I did it was to write a vex sop to do it as I couldn't find a decent way to do it with anything built in.
You might be able to do it now with a combination of the align sop and a primitive sop but I haven't tried it.

The trick is finding just the right hammer for every screw


flyingc: Member; 160 posts; Joined:; Offline

May 10, 2009 12:48 p.m.

I wired a digital asset.
but i can't import selected primitives to “groupb” after select a polygon. So you must type a number in order to extrude a face
Speak in English is a tired thing for me.. sorry

Attachments:
Poly_sweepPoly.hipnc (164.1 KB)
swp.jpg (148.3 KB)


Simon: Member; 2199 posts; Joined: July 2005; Online

May 11, 2009 4:36 a.m.

You need to setup an ombind

something like this

omsbind -t sop polycuspbevel:group prims “First input” “Select the polys to test for cusping” 0 1 poly 0 “” 0

The trick is finding just the right hammer for every screw


flyingc: Member; 160 posts; Joined:; Offline

May 11, 2009 6:09 a.m.

Simon
You need to setup an ombind

something like this

omsbind -t sop polycuspbevel:group prims “First input” “Select the polys to test for cusping” 0 1 poly 0 “” 0

how and where should I put this code?


Simon: Member; 2199 posts; Joined: July 2005; Online

May 11, 2009 6:13 a.m.

You can just run it in a textport whilst testing, you'll need to modify it to match your node.
Then when you have it working add it to the script section of your asset and change the event handler to “before first create” (I haven't tested this though as I use the method below)

or

you can put it in a 456.cmd file in your scripts directory.

The trick is finding just the right hammer for every screw


flyingc: Member; 160 posts; Joined:; Offline

May 11, 2009 7:03 a.m.

I try it and it does works!
many thanks!


flyingc: Member; 160 posts; Joined:; Offline

May 11, 2009 7:48 a.m.

Another question, I left last option as “*”,but couldn't select group from left list.How to import predefined group to the list and select it?

Attachments:
swp2.jpg (14.2 KB)


Simon: Member; 2199 posts; Joined: July 2005; Online

May 11, 2009 8:41 a.m.

If you create that group field by dragging the one from the group node into the type properties dialog it will set it up for you.

The trick is finding just the right hammer for every screw


flyingc: Member; 160 posts; Joined:; Offline

May 11, 2009 10:27 a.m.

I asked a stupid question but it take me a long time to think.

thank you


flyingc: Member; 160 posts; Joined:; Offline

May 11, 2009 7:23 p.m.

One more question.
I wish to use Ramp(float) type Parameter to control extrude section scale ,so i name the parameter to “scalec” and wire it to scale parameter of the sweep Sop in my network with “ch(”../scalec").
but it doesn's work correctly.

why?

Attachments:
swp2.jpg (69.1 KB)


edward: Member; 7725 posts; Joined: July 2005; Offline

May 11, 2009 10:17 p.m.

Instead of ch(), you should use chramp().


flyingc: Member; 160 posts; Joined:; Offline

May 11, 2009 11:10 p.m.

All thing is ok ,thank you

Attachments:
swp2.jpg (52.0 KB)

Quick Links

                    
                        Search links
                        Show recent posts
                        Show unanswered posts