This is my first time here and I hope I'm posting this in the right section if not well then move it.

For the life of me I can't figure how to Manipulate, Twist ->Bend my tube geometry.
I'm trying to model a bike frame (Harley). The tutorials just aren't helping me with this type of operation.
I would be more than gratefull if someone could point me towards a good tutorial or give me the right pointers. ops:

Hi Zenfu,

Please make sure you select Polygons, Mesh or Nurbs as the Primitive Type for the tube instead of Primitive.

Cheers!
steven

stevenong
Hi Zenfu,

Please make sure you select Polygons, Mesh or Nurbs as the Primitive Type for the tube instead of Primitive.

Cheers!
steven

I'm sorry Steven I worked on that a while and no luck
I am a definate noob with limited experience but I have gone thru all the tutorials and I just can't bend a tube how silly is that, such a basic operation. :cry:

First make a tube sop. Change the primitive type to nurbs.

Then right click on the down arrow of the tube sop and append a twist sop. Change the operation type to blend. Move the strength slider.

Alter the axis values.

Try looking at the tutorial videos if you're having problems with the interface.

Henster
First make a tube sop. Change the primitive type to nurbs.

Then right click on the down arrow of the tube sop and append a twist sop. Change the operation type to blend. Move the strength slider.

Alter the axis values.

Try looking at the tutorial videos if you're having problems with the interface.

I need to “Bend” not “Blend”

LIke taking the end of a bar in each hand and bending it.

I think a far more controllable way would be to generate your tube from a curve though.

1. With your mouse in the SOP viewport, hit Tab > Curve.
2. Change the Type to NURBS in the Parameters pane.
3. Draw your curve in the viewport and right-click when done.
4. Tab > Circle. Change the Type to NURBS in the Parameters Pane. Adjust the radius of the curve using the viewport handle.
5. Tab > Sweep. Read the blue text in the status line. Right-click right-away as you already have the circle selected. Read the blue text in the status line. Now click on the curve, right-click to complete.
6. Tab > Skin. Right-click once as you already have the u sections selected. Right-click a second time as we have no v sections. In the Parameter pane, delete the contents of the U Cross-sections so that it will always use all the circles found. This will keep your setup procedural.
7. In the Operator menu of the SOP viewport, choose Footprints and Templates > Clear All Footprints.
8. With your mouse in the SOP viewer, hit Home and then Shift+PageDn. This moves your current editing sop to the curve again for you to adjust the shape. You can even insert more points into the curve. Read the blue text in the status line at the bottom on how to do this.
9. Hit the End key to go back to the bottom of the chain.

There's probably faster ways to do this in the network editor but I've described how to do it completely in the viewer and parameter panes.

As a beginner, the free online Houdini course at www.3dbuzz.com is the best place to start. In one of the assignments, modelling a lamp is required and many people have run into this type of modelling problem already and have very good solutions for how to do this in the course forum.

Zenfu,

I saw your post on 3d Buzz and figure I'll reply to it here instead since this is where it started. For high curvature, the method doesn't seem to work too well. To fix that, simply change the type of your curve to Bezier.

When I used the curve/circle/sweep method to make my lamp cord I didn't even use the skin sop after the sweep sop. Within the sweep sop I went to the Output tab and set “Skin Output” to be “Skin with preserve shape and auto closure”. What is the difference between doing it my way here and your way, Edward? Or, as long as you get the result you're looking for, that's all that matters?

Hmm. You're right. I tried that with a Bezier Curve w/Breakpoints method and a regular Skin with Auto Closure on the Sweep seems to work fine as well.

The more I use Houdini, the more I see there are different ways to do things.