Moving Control Points

[kmwhitt]

I have decided to go ahead and start using FormZ 7 - have been using V6 for years now.  Working with Nurbs is alien to me.  Are there any good tutorials that show techniques for moving control points accurately?  Most of the YouTube vids I've seen show free form design with random placement to achieve the desired look.  I'd also like to see techniques on how points can be manipulated in the 3D viewport.

 

Is there a way to "slide" a control point while maintaining its relationship to adjacent control points?  Any recommendations on videos or books would be greatly appreciated.

 

Thanks,

 

Kevin

[DennisA]

Have you checked out the manual, webinars & tutorials? You can access in help pull down menu.

[kmwhitt]

Yes, I have looked at the tutorials and they have been helpful.  I am running into some things -
 
I am attempting to model the attached cup pull.  I have two trimmed surfaces - center and outer ring.  I need to move control points outward on the center of the cup pull to create a bulge instead of it being depressed as it is now (red arrow).  When I move the control points, the edge of the middle surface separates from the outer ring even though I don't touch the points around the perimeter.  I understand this is to be expected as these are nurbs.  However, I have tried attaching and stitching and it continues to move.  How do I go about editing this as one object?  Thanks!

[kmwhitt]

How do I upload an image on this forum?

 

FOUND IT!

[kmwhitt]

Anyone with any advice?

[palarsen]

Snapping to controllpoints work, but not snapping to self, or original. This is needed, when aligning controllpoints

[kmwhitt]

I'm moving along.  I am not happy with the shape I've got, but it it will have to do.  I can use Nurbs blend or merge to fill the slight gap if I can get it to work.

 

I have run into another issue using Nurbs Merge - please see attached.  I am merging parts 1 and 2.  The operation gets completed, but the shape becomes distorted.  Why?  Is it necessary that I reshape after completing this operation?

 

Thanks in advance,

 

Kevin

[Tech]

Here's some other options for creating this type of shape.

Method 1: Create desired bulge in original cutting surface eliminating the need to edit the surface after.

1. Create double curved cutting surface using nurbs tools or the primitive hyperbolic paraboloid.

2. Use Surface Split Two Way option and delete the resulting pieces you don't need.

Method 2: Recreate the cut surface to convert trimmed nurbs into a plain nurbs.

3. Use Uncover tool to convert cut surface to a wire edge. Use Break tool to break edge at midpoint, (observe two points in edge).

4. Use Nurbs Loft By Tight Lofting tool to loft a nurbs surface between the two edges. Use Nurbs Reconstruct to control the number of control points on nurbs surface.

Note, you can edit any controls except the ones on the outer boundary to maintain the edges with the other cone object. You can also Stitch and UnStitch the face as often as needed to edit the shape. When you Unstitch you'll need to use the Convert to Nurbs tool again to access the nurbs controls.

[kmwhitt]

Thanks, Tech Support - making sense now!