Creating Type of Cord

[Falam]

I need some help on how to create this cord. I've tried extruding along two profile curves, and I've thought about the tool "deform by UV map", not too sure about that method, and I've tried extruding along a curve, the cord shears, sorta.

[rimg=600]http://i.minus.com/ibcDDcl34RR1w3.JPG[/rimg]

Moderator edit: resized the image with our rimg tag (see our tag FAQ) - HB

[manuelriedl]

try the 'rope rig' viewtopic.php?f=19&t=2512
I've never personally used it, but it seems to be just what you need..
Apart from that you might also want to check out http://www.matkovic.com/anto/ice.html, or just browse http://rray.de/xsi/ for compounds.

p.s. please edit the size of your images. they look like they're twice my screen resolution..

[Mathaeus]

well there is no such rope/screw generator on my site. Usually it's possible to create this kind of forms, by using standard operators, available in any 3d app which have operator stack.
XSI bend could be tricky because it won't adjust itself to size of bounding box, like equivalents in some other 3d app, so you'll want PI number somewhere. But that's all.
When doing such things, I think it's good idea to work on small, repeatable segment, and fill the rest with clones. There's much better feedback in this way.

Once you have a straight rope, deform it by curve or something.

[rray]

Displacement could work for this too (with an appropriate texture)

[Falam]

well there is no such rope/screw generator on my site. Usually it's possible to create this kind of forms, by using standard operators, available in any 3d app which have operator stack.
XSI bend could be tricky because it won't adjust itself to size of bounding box, like equivalents in some other 3d app, so you'll want PI number somewhere. But that's all.
When doing such things, I think it's good idea to work on small, repeatable segment, and fill the rest with clones. There's much better feedback in this way.

Once you have a straight rope, deform it by curve or something.

Your comment was right, and your technique is directly what I was hoping for, this is very clever, thank you. I'm going to give this a go

Displacements maps is another route I could have gone, true, although Mathaeus method is what I really was aiming for, thank you as well for the tip.

[Falam]

@Mathaeus

The technique worked, because the edges are offset, how do you merge ? Otherwise, the results are perfect. I can't figure out how to get it to merge.

[Mathaeus]

@Mathaeus

The technique worked, because the edges are offset, how do you merge ? Otherwise, the results are perfect. I can't figure out how to get it to merge.

Well it shouldn't offset before merging. Actually you'll first want to "close" the segment, by "weld boundary point/edges", then you merge segments. For both, you'll want a small distance for merging/welding. It's good idea to freeze operator stack before these two operations, especially if you used some of them in animation region ( like in pic).

[Falam]

@Mathaeus

The technique worked, because the edges are offset, how do you merge ? Otherwise, the results are perfect. I can't figure out how to get it to merge.

Well it shouldn't offset before merging. Actually you'll first want to "close" the segment, by "weld boundary point/edges", then you merge segments. For both, you'll want a small distance for merging/welding. It's good idea to freeze operator stack before these two operations, especially if you used some of them in animation region ( like in pic).

The cord is nearly perfect, if not perfect If I could create an extrusion between two profile curves, that is what I was originally hoping for, while creating the same effect

[Daniel Brassard]

Hi Falam,

I would use ICE to create the curve helix using these formulas

x = r cos(a u)
y = r sin (a u)
z = b u

where

a is the number of revolution around the axis (in this case the z axis)
b control the distance between each revolution
r is the radius of the circle of revolution
u is between 0 and 2Pi (0 <= u <= 2Pi)

That way you can create a curve or strand of any length and then use it for input to your profile curve to rotate around.

Once you have a straight rope, deform it by curve or something using the traditional tools in Softimage.

Just a thought!

Cheers!

P.S. You can extrude along the strand or use the StrandtoCurve compound for that trick if you don't already have it!

viewtopic.php?f=15&t=672

Or follow the example mentioned on Stephen Blair Blog

http://xsisupport.com/2011/04/14/basics ... n-strands/

If you’ve looked into the Modeling_Columns_from_Strands sample scene, you’ve seen that there’s a Create Spiral Strands compound that creates the strands used for the extrusion.

[rray]

also possible using extrude along axis:

extrude.jpg

[Falam]

@rray - With the default extrude along curve, I can't use a curve as the input.

@Daniel - What nodes do I enter in those values to create a helix ? I see where you are heading, if I could create a helix and it follows a curve, then using a curve as profile for the radius of the helix, that would probably match the image closely, if not precisely, in conjunction with "building my own strand". Sorry, I haven't delved that deep into ICE yet

[Daniel Brassard]

@Daniel - What nodes do I enter in those values to create a helix ? I see where you are heading, if I could create a helix and it follows a curve, then using a curve as profile for the radius of the helix, that would probably match the image closely, if not precisely, in conjunction with "building my own strand". Sorry, I haven't delved that deep into ICE yet

I'll put the ICE tree together and provide you with the compound when I have a chance. Did it partially yesterday (most of the calculation that will affect the strand) but want to tweak the options for versatility / ease of use.

It will be very similar to the parametric topology compounds I play with.

Dan

[Falam]

Thank you.

[Daniel Brassard]

I worked a bit more on the ICE tree but it has some major headaches with the strands. In order to get good subdiv, one's need to crank the subdivision high. At 1000, Softimage will crash because the build linear interpolated array produce too small numbers and soft think they are all zeros.

Then their is the odd behaviors with the strands attributes/parameters themselves that just make it a poor solution for your problem. The compound is too unstable to be release at this time but if somebody want to help, well I'll share it.

Anyway, here is a few screen grab of the ICE tree and result for information. The ICE Tree is not optimized yet, more work to do in there.

To note:

• The strand ICE tree is on an empty particle cloud.
  The ICE tree extrusion along strand is on an empty polymesh
  And then their is the curve profile on it's own.

I am thinking now doing this thing via script/PPG

Something to investigate would be: can it be done via Keyvis Curve Tools, Power Extrude or Tiny Curve Extrude? My bet is on Power Extrude! Worth testing.

http://vimeo.com/27256396
http://rray.de/xsi/


Cheers!

[Falam]

I worked a bit more on the ICE tree but it has some major headaches with the strands. In order to get good subdiv, one's need to crank the subdivision high. At 1000, Softimage will crash because the build linear interpolated array produce too small numbers and soft think they are all zeros.

Then their is the odd behaviors with the strands attributes/parameters themselves that just make it a poor solution for your problem. The compound is too unstable to be release at this time but if somebody want to help, well I'll share it.

Anyway, here is a few screen grab of the ICE tree and result for information. The ICE Tree is not optimized yet, more work to do in there.

To note:

• The strand ICE tree is on an empty particle cloud.
  The ICE tree extrusion along strand is on an empty polymesh
  And then their is the curve profile on it's own.

I am thinking now doing this thing via script/PPG

Something to investigate would be: can it be done via Keyvis Curve Tools, Power Extrude or Tiny Curve Extrude? My bet is on Power Extrude! Worth testing.

http://vimeo.com/27256396
http://rray.de/xsi/


Cheers!

The results you posted are very good, very similar as well to that of the image. I did try Power Extrude, it doesn't allow me to use a curve profile to deform the shape of the extrusion after it's extruded. It only allows me to have, two curves, the original radius/shape of the curve and the curve that the radius curve will be extruding along. It seems your ICE tree does the same thing, probably with more flexibility if you are able to use a curve to deform the extrusion profile ?

[Daniel Brassard]

Hi Falam,

The curve profile is not a problem, you can shape the profile in any way you want (scaling, translation, rotation, deformation and it will dynamically show the result on screen (that's how I got the shape close to your pic by taking a curve circle and deforming it to approximate the profile).

The strand behaviors and amount of point you need to generate, that's what get in the way. If the subdivision don't match, you get weird twisting along the main curve and the profile get bent out of shape.

Then when i try to duplicate the strand, the duplicate origin is stuck to the original and does nor follow the duplicate.

Another problem is, if i make the tube longueur than 4 units, I need to crank the subdivision pass 1000 and Soft crashes.

And it goes on and on. Too bad we cannot work on curve directly with ICE. Script, in the other end, that is relatively easy to do.

I think Power Extrude is the answer. You can change the profile to what ever you want, and there is a twisting parameter that should allow us to turn around the main curve. I will test it tonight and see what parameter you need to adjust.

Dan