Notifications
Clear all

[Solved] How to mesh imported files and how to morph one geometry into another geometry

7 Posts
2 Users
0 Reactions
1,077 Views
Posts: 6
Topic starter
(@nicolepac)
Unpaid Intern
Joined: 5 years ago

Hi there. I noticed in one of your intro youtube videos on Unpopular Mechanics that you do a lot of work with building finite element models of human anatomy. I am doing something similar for a project! I have two .step files of a bladder and would like map the nodes from one bladder to the surface of the second bladder. I was reading a paper that did a similar thing using HyperMorph in HyperMesh. I would like to know a few things: 1. how to properly mesh my imported .step files, 2. if both parts need to be meshed, and 3. how to navigate HyperMorph to achieve this morphing of one shape into another shape. I am also not sure if I need to set up global/ local domains using those yellow seed things.

6 Replies




Negative Volume
Posts: 667
Admin
(@negativevolume)
CEO
Joined: 6 years ago

Hi @nicolepac

What you are trying to accomplish is commonly called Morphing. There are many ways to do this, one of the most common being a thin plate spline method. I have limited experience with Hypermorph. I’ve managed to morph a wrist bone from one size to another but have never really gotten comfortable with the process. I would try to setup a global domain for the source and target .step and try Hypermorph with that. 

Let me know if you encounter issues along the way, I’ll be happy to help!

Reply
3 Replies
(@nicolepac)
Joined: 5 years ago

Unpaid Intern
Posts: 6

@negativevolume

I received advice to create a surface out of one .step file and a mesh on the other .step file... then to morph the mesh onto the surface. Does this sound right or should I mesh both parts and then make one of them into a surface.

When I try to make a bounding surface on one of my .step files, the bounding surface tool identifies 891 faced but it cannot finish the job because it says that there is no enclosed volume found. I do not have any open edges (I looked for red lines but there are none... all are green). Do you know how to fix this?

...I tried to make my bounding surface directly on the imported .step file. Does it need to be meshed first? I tried to mesh it and make a bounding surface from there, but the algorithm seems to ignore the mesh and bound surfaces directly on the .step file.

Thanks again for your time and help. Much appreciated.

Reply
Negative Volume
Admin
(@negativevolume)
Joined: 6 years ago

CEO
Posts: 667

@nicolepac

Correct, so you want to mesh 1 step and use the other as the other step as the target to morph the mesh to. 

Before that though, you want to make sure that both step files are "solids" within Hypermesh. This process consists of what you mentioned, creating bounding surfaces from the step files. 

Just to clarify, go to the "Geom" side bar, then click Solids, and then click on the icon that looks like a box with red lines and is called Bounding Surfaces if you hover over it with your mouse. From here you will select all of the surfaces for 1 step file and click create. If it works correcting then it will show the object as a transparent green color with green lines. If it doesn't work, then there are some gaps within the individual surfaces of the step file. 

To fix these, move back to the "Geom" tab, Edge Edit, and then Toggle. From here, make the cleanup tol (tolerance) = some value that is reasonable for closing any gaps between free (red) edges between surfaces. Then you will just click these free edges and it will close the gap. 

You said that you couldn't find any free edges though, but it could be just an issue of locating them. Try to turn the surfaces to wireframe mode (image below) and this may help you locate these. 

If you still can't find them, you can also try to go to autocleanup in the "Geom" toolbar and edit your parameters so that it doesn't overly simplified your geometry. 

Let me know if anything of this helps. 

Reply
(@nicolepac)
Joined: 5 years ago

Unpaid Intern
Posts: 6

@negativevolume

Thank you! I will have to get back to you tomorrow when I have access to a computer with the software!

Reply




Posts: 6
Topic starter
(@nicolepac)
Unpaid Intern
Joined: 5 years ago

@negativevolume

Hi! I tried what you suggested above but am still having issues. Would it be possible to have someone take a look at my .step file? I am not sure what else to try and perhaps someone more experienced could determine the issue.

Reply
1 Reply
(@nicolepac)
Joined: 5 years ago

Unpaid Intern
Posts: 6

Got it to work!!!!! Many thanks for all of your help 🙂

Reply







Share: