# NURBS Cylinder

## Recommended Posts

I have am finally getting the opportunity to learn some of the 3d power pack tools. I am trying to make a cylinder with a smooth rounded top. I started with an ellipse, extruded it and converted it to nurbs. Then I selected the center vertex of the top surface and moved it up to get the curvature. This happens.

The outside ring of the ellipse is no longer touching the rest of the object.

How can I have this be a solid object with nice smooth edges and no "holes"?

I was originally going to start with an elliptical sphere and subtract solids from that, but I can't figure out a way to make an elliptical sphere either.

Any tips appreciated!

Thanks,

Andy

##### Link to comment

The easiest way to do it would be to extract the curve from the top of the cylinder. Duplicate that curve and move it up in the z direction and scale it to about 50%. Then place a 3-D locus at the apex of the dome. Then use the loft tool to connect the 3 objects together. If the dome is too tall you can simply look at it in elevation and grab the middle selection handle on the top and drag it down.

I hope this makes sense.

Good Luck

##### Link to comment

This exact shape was discussed recently at http://techboard.nemetschek.net/ubb/ultimatebb.php?ubb=get_topic;f=12;t=002131 . The advice for reading the thread is to ignore my posts and read Mike's.

The summary is to use 3D PP's half sphere tool to get a hemisphere of the right diameter. Convert to nurbs. Squash the hemi- to set the ellipse minor axis. Then extract the bottom curve, move it to the depth of the cylinder and loft to create the cylinder base. Full credit for the answer to Mike...I just plagerized his answer.

##### Link to comment

Thats funny, somehow in the way Andy his described the problem it didn't click for me that it's the same situation. Anyway both methods will work, just keeps reminding me that theres more than one way to skin a cat.

##### Link to comment

Cool, Glad you got it.

Thanks

##### Link to comment

I would just extrude a circle. Use the sphere tool, convert sphere to nurbs. Squarsh it down and line it up with the cylinder and add solids.

[ 03-20-2003, 09:03 AM: Message edited by: Marc ]

##### Link to comment

How would you clean up the line where they join that show white artifacts in your render? Better, worse, or indifferent, those don't seem to happen when the actual curve of the circle is lofted.

##### Link to comment

It seems to me that this should happen automaticaly after all all you did ws to loft the center section.... there must be some bugs with the power pac stuff

##### Link to comment
• 4 months later...

Why not a simple sweep with a rounded edge. When you round the edge of a swept cylinder it becomes a nurbs shape. and you can dimension and control the shape to exact size.

## Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

Only 75 emoji are allowed.

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×

• KBASE
• #### MARIONETTE

×
• Create New...