Help Modeling a Lens

[trashcan]

I want to create a lens that is 4.66" in diameter and 1" tall. 

 

The way I created it was:

1. Create a flat circle with target diameter
2. Create a hemisphere (diameter doesn't really matter, just needs to be a lot bigger than the flat circle)
3. Align the flat circle vertically so it matches the diameter at a specific height of the hemisphere
4. Use the split tool to create a solid section
5. Take that new almost-there lens and convert it to NURBS
6. Adjust the height to 1"

 

 

If I instead:

1. Create a hemisphere at 4.66" in diameter
2. Convert to NURBS
3. Adjust the height to 1"

 

I end up with more of Pancake shape (V2) then a lens shape (V1):

 

Does anyone have a recommended workflow for this?

 

 

[markdd]

Have you tried the Sweep command? 

 

The other command which I think may give you better results is the Revolve with rail command from the 3D Powerpack. That will give you a Nurbs Surface. 

 

If you want to then put a cap on the bottom, then use the extract tool to get the bottom ring and convert the resulting Nurbs curve into a Nurbs Surface and Add the Solids together (Add Solids command) 

Edited May 28, 2020 by markdd

[trashcan]

@markdd using the sweep command works like a charm and gives you the right flexibility to control the arc type for the lens (I.e., V1 vs V2 from previous post). 

 

Revolve with rail works too, but the base shape (I.e., the lens arc) is harder to modify after you've done the action. If you double click the new NURB "lens" it gives  you individual control of each point:

 

Ideally you can revise that arc if you need to and it seems like you can really only do that intelligently using the sweep command:

 

 

I'm also seeing this extended geometry with the Revolve command and I'm not really sure what that means.