Variable Section Sweep Problem

[soccer8888]

Hello,


I have a set of 3 3D splines that are stacked on top of one another. They have slightly different shapes, but I need to create a solidextusion that 'morphs' into these shapes as it goes from the 1st to the 3rd. I believe I need to use variable section sweep, but no matter what I do, the green check never un-grays. This was so easy to do in UG, I can't believe its this difficult. I have 3 guide lines or trajectories for the extrusion as well, shown in red. I tried the help, but it still didn't work. Anyone have any tips or walkthroughs/demos?


View attachment 3427

 

[vlad1979]

Looking at this I don't think you need var sec sweep but rather swept blend / with select sections.

 

[soccer8888]

That could very well be why I'm having issues. What's the difference between the two?

 

[TWINTURBOTOM]

i am not sure if i interpret what you are doing correctly but...if you want to be a professional then this is what you do


create 3 datum graphs...each one being one of the three curves you need


create a straight curve by equation...OR instead of creating 3 datum graphs create 2 datum graphs and the 3rd curve you omitted from the graph step make a regular datum curve...


now select your datum curve (whether it's the straight line or a curve); VSS when oriented into sckether draw a spline with 2 or 3 points (depending on one many datum graphs you have done)...then write relation: sdXX=evalgraph("curve1",trajpar*L) for one of the points and do the same for the rest.....L being the length of thetrajectory...this relation will use the Y values of your datum graph as it travels along it's curve..think of the x values in the graph as being the distance the cross section travels along the curve...so when the section is at X 1 on the trajectory it will use the Y value of the graph at the graphs x1 (unless you change the "L" variable after trajpar)


this method allows you to control a simple cross sections dimensions as it travels through the curve...


if thought out well enough this type of method allows you to completely control the cross section with parameters...so you can modify with out editing definitions!... good luck!!!





soccr...swept blend is basically two features in one.....the later bing a blend....cross sections (which you can select, as stated above, as being your curves)that areblended (or in your words "morph")together... the swept part refers to a sweep which means a cross section travles a trajectory or path..





have fun!@

 

[mgnt8]

Splines don't work very well with VSS or Swept Blend. If I were you, I would use either boundary blend or Style.

 

[soccer8888]

I'm finding that out about the splines...can you create a solid by using boundary blend though? I've never used style either... Man, I feel like a complete novice.

 

[james.lynch]

I sweep profiles along splines on a daily basis with no problems. Where had you had problems??


you can create the side surfaces by useing a boundry belnd.


Simply start the tool, then click on the lowest curve, then middle then top, then,click on the second direction and click onone of the edges that join the three first curves of the end rectangle, then the middle curve (on the left of the picture) and then ontheother edge of the rectangle.. and there is your main surface.


as for the top and bottom, well thereare a few ways. are the splines full3d curves? le tme know if you have problems and I can explain one or two methods..


once yo have created all surfaces, simply merge them together (edit/Merge) then select the quilt an dsolidify (edit/solidify) job done!


I'm sure there are faster ways and I'm sure I could get a sweep to work.. there's always more than one way to skin a cat!

 

[soccer8888]

I have problems when I go to create it after choosing the sections and trajectories. It says it has a problem with the blend.





The splines are only 2 curves. the full curved spline, and the shorter straighter spline connecting the ends of the first one (on the right of the picture). I'd be interested in finding a way to get the top and bottom surface modeled and making the solid that way. Thanks for all the help thus far.

 

[mgnt8]

Don'tuse splines in your section, but you can definitely use splinesas your trajectorys. Which curve is your section & which curves are your trajectory? Maybe you should post the model so we can get a better look at. Regardless, boundary blend would solve this problem in a minute.
Edited by: mgnt8

 

[soccer8888]

I did solve it using boundary blends and solidfy although it wasn't perfect because the top and bottom surfaces had little wrinkles in them. Regardless, thanks for everyones help!