Extrude / Sweep a cross-section profile along a path

[oompa_l]

hi

I am new to max. I am looking to create what is essentially a volume that might contain a switchback fire-staircase - imagine a tube that goes from horizontal to an inclined orientation and then back to the horizontal and so on. I want to maintain a consistent RECTANGULAR cross section along the tubes length as it turns and becomes inclined. I have tried to extrude a rectangular spline along the centreline of the path but the volume has issues - as the section turns in plan 90 degree it does not understand how to handle the corner. I have also tried with nurbs but this doesnt seem like the right way to go. I feel like this is a very simple problem but I am not getting anywhere.

also, I should mention that i am looking for a solution that keeps a relationship[ back to the geometry I use to create it so If I want to tweak the path of the tube I literally am doing just that and not modifying the mesh directly.

thanks for your help in advance.

g

[arshiel88]

I still consider myself as a beginner in 3dmax but have you tried doing the model in AutoCAD and then linking the file to 3dmax? I think its easier and more accurate than doing it in 3dmax. Besides the plan will come from AutoCAD, right? I only use 3dmax's modeling tools/modifiers for desperate situations.
Anyways, you may try Loft under Coumpound Objects rather than extrude along path. if I remember it correctly, you can control the twisting with that operation.

[oompa_l]

i dont know how to model in autocad....i am afraid of entering those waters. I will look into lofting, but I would rather have only one sectional element over the course of the entire length of the "tube" I was describing.

thanks

[dellis]

Gabriel,

Look into the Sweep modifier...it will do exactly what you need. If you need more help post back here!!

[oompa_l]

thanks dellis. I am quite pleased with the sweep command. One problem though - which maye you can fix - is that even when I choose that the source section becomes either instanced or referenced the connection back to the swept shape is lost. This is quite an important aspect of the tool for what I am working on....I have tried extracting the shape after the fact and I am getting the same thing. what's up with that?

also, can you set scale key frames along the length of the chosen spline as you would be able to do in a loft? it would be nice to be able to adjust the scale and using bezier curves ease in and out of these points...

[dellis]

Gabriel,

Sweep doesn't really have the animation capabilities like the loft modifier does...there are work arounds however...but they would depend on the scene. As far as being able to mess with the shapes after:


You can edit the orginal path by going to the modifier panel and then going down the stack(below the sweep modifier)and go into the sub-object mode for the line and do whatever editing you need.

You can also edit the shape of the sweep by just editing the original shape that you chose in the sweep modifier. They are linked....if you edit the shape you will see the changes immediately to the sweep object.

On of the cooler features that the sweep modifier has is that it can handle multiple lines...even if they are intersecting this is impossible with the loft modifier.

Hope this helps.....