How to loft topo lines into a solid

mark_schneider770

I have a student that has traced out all the topo lines for an island and offset each plane at a .1 inches = 100 feet scale, he was hoping to loft them all and then 3D print the model. But he can not loft them (neither can I) are there limitations on lofting that I misunderstood? Is there a better way to do this?
I also would attach a link to it, but I don't know how.
Thank you
Mark

EvanReese

The best way I can think of is to use the offest surface command with the value set to 0, then box select all of the sketch faces to convert them to surfaces. From there you can export it as a RHINO file and use the DupBorder command in rhino to get curves from the surface edges. You don't need these curves to use the heightfield command in Rhino though. For that, you need to find a way to produce a bitmap as the input with the greyscale value representing the height. You could try getting it from Onshape, by making all of the surfaces black, dropping the alpha some, and screenshotting it like this. You'll still get the lines, so you'd have to find a way to blend them. In poking around for a better source for this depth map, I found this instructable about printing topo maps that might be the best solution for what you're after.

steve_shubin

@mark_schneider770

If you’re not able to get that solid with rhino, then you might be able to do it with formZ. You’ll have to check with the makers of formZ to see if the educational version will give you access to their Terrain  tool

Great advice on that offset surface tool @Evan_Reese

 I was able to bring that into formZ no problem and then awls I had to do is convert the lines to NURBS I think it was, then group select all of the topo lines, select the Terrain tool, then select the boundary

Then a few Booleans to trim around the island and then it’s a matter of applying materials

By the way I’m not that great at customizing materials. So I’m sure somebody else could come up with a better dirt or rock surface and a better water. But I’m just not that great at texturing and materials and rendering.

But hopefully you can get the idea on how it was no problem taking those TOPO lines and coming up with this shape without any problem

mark_schneider770

Sorry here is the link https://ferndalesd.onshape.com/documents/d6c8e540de1b7557b6fd234e/w/f4b341765ae6cc2fdd0ccde0/e/b73de10d7a0962acbddda3d2

bruce_williams

the document is view only.  please see here how to share a public doc.  https://forum.onshape.com/discussion/9107/forum-post-checklist-read-this-first#latest

mark_schneider770

Here is the link to it that is not a version, which I did previously. Otherwise, I don't see a way to make this document public, it is an enterprise account and there is no toolbar at the top of onshape that allows to click on the Globe to make it public.
but I doubt it will let you into our Enterprise account either. 
https://ferndalesd.onshape.com/documents/a3a123d5130d03457ffe1430/w/4b0fab9322f17b200b1ca6a8/e/0759aada55091e807c8c0ba9

Thanks

mark_schneider770

OK, it took me a couple days, but I moved it from the Enterprise account to free account so that the drawing is now public
https://cad.onshape.com/documents/a3a123d5130d03457ffe1430/w/4b0fab9322f17b200b1ca6a8/e/0759aada55091e807c8c0ba9
Thank you

EvanReese

If you need this to be smooth, I don't think Onshape is the right tool. You might do better with Rhino's heightfield command or some kind of displacement map in a mesh modeler.

If smooth isn't super important then you can do this with one extrude feature and one boolean to merge them like this

mark_schneider770

Thanks Evan, that is kind of what I thought. Do you know an easy way to export it to rhino? I found  myself exporting every spline individually and I know there is probably a much better way.

EvanReese

The best way I can think of is to use the offest surface command with the value set to 0, then box select all of the sketch faces to convert them to surfaces. From there you can export it as a RHINO file and use the DupBorder command in rhino to get curves from the surface edges. You don't need these curves to use the heightfield command in Rhino though. For that, you need to find a way to produce a bitmap as the input with the greyscale value representing the height. You could try getting it from Onshape, by making all of the surfaces black, dropping the alpha some, and screenshotting it like this. You'll still get the lines, so you'd have to find a way to blend them. In poking around for a better source for this depth map, I found this instructable about printing topo maps that might be the best solution for what you're after.

mark_schneider770

Thanks Evan!  We ended up extruding and filleting then exported the solid to rhino, in rhino we use the drape command to create a smoother surface , trimmed it up and hopefully will be able to make that into a solid.

EvanReese

mark_schneider770 said:

Thanks Evan!  We ended up extruding and filleting then exported the solid to rhino, in rhino we use the drape command to create a smoother surface , trimmed it up and hopefully will be able to make that into a solid.

great! that sounds like it ought to work better than the heightfield suggestion. You may be aware, but there's a Smooth command in Rhino that might help clean up the draped surface some too.

steve_shubin

@mark_schneider770

If you’re not able to get that solid with rhino, then you might be able to do it with formZ. You’ll have to check with the makers of formZ to see if the educational version will give you access to their Terrain  tool

Great advice on that offset surface tool @Evan_Reese

 I was able to bring that into formZ no problem and then awls I had to do is convert the lines to NURBS I think it was, then group select all of the topo lines, select the Terrain tool, then select the boundary

Then a few Booleans to trim around the island and then it’s a matter of applying materials

By the way I’m not that great at customizing materials. So I’m sure somebody else could come up with a better dirt or rock surface and a better water. But I’m just not that great at texturing and materials and rendering.

But hopefully you can get the idea on how it was no problem taking those TOPO lines and coming up with this shape without any problem

mark_schneider770

Thanks for the suggestion, that does look a bit better than what I was able to generate!