mesh modeling and solid editing

[basshead]

Hi, so basically i made a number of individual mesh shapes and overlapped them to create one continuous shape. then i converted the mesh into a solid and grouped them together. the reason was to be able to use the shell function on the solid, but for some reason it s not working. i also tried converting the mesh into a surface and and offsetting it inwards, but it s not working either. the reason i want to do this, is to have a hollow shape with a specific outer shell thickness.

 

any suggestions on how i can convert these meshes into a hollowed out shape of a specific outer shell thickness??

 

DWG file

Edited January 22, 2011 by basshead

[basshead]

can anyone help me, pleaseeeeeeeeee??

[JD Mather]

You haven't attached anything here, not a dwg, not even a jpg.

[basshead]

sorry, still new to this. i attached the dwg with which i m having a problem. there are 3 versions of the same model in the drawing:

 

the top is a solid with individual volumes grouped

the middle is a solid with separate volumes

the bottom is a mesh with separate volumes

 

thanks

[JD Mather]

Well I don't see any files, but in general, think of working in 2d and offsetting a circle towards the centerpoint. Your offset curve can get smaller and smaller but not zero radius or less than zero. The same kind of thing happens when trying to Thicken or Shell but with your complex 3d geometry it might not be apparent where a curvature is being offset past zero radius (and therefore failing).

[basshead]

ok thanks, i uploaded the file to a website because it is too big to attach. the link is in the first post at the top.

[SEANT]

That will be a rather complex procedure for AutoCAD. A couple of suggestions, perhaps:

Move the model closer to the WCS origin.

It looks like the shape will only support a rather small shell distance (

The process may need to be sub divided to reduce the complexity of any one operation.

Here is an image of a small sample.

[basshead]

i tried moving the model and i entered a thickness of 0.15m but it still isnt working. could you maybe go into more detail on how u managed to do it?

[SEANT]

I started simple by using only two of the mesh shapes. Those shapes, once solidified and unioned, would not SHELL with a thickness of 1, but did okay with a thickness of .1.

Task Manager spikes rather dramatically with the operations, though. It is not hard to imagine hitting the ceiling if too many shapes are processed simultaneously.

[basshead]

i tried again, but it s still telling me 'no solution for a vertex'. i also tried the process by creating a simpler mesh, converting it into a solid, and applying the shell function with 0.15m thickness, but the same statement is displayed below. i think the problem is when converting the mesh to a solid, because when i make multiple solid primitives, unionize them and apply shell, it works. i cant understand what i m doing wrong. and what do you mean by "using only two of the mesh shapes"? to create a shell around the whole model, dont you have to unionize all the meshes and then apply shell? or is there another way?

[SEANT]

It doesn’t look like AutoCAD will shell some of those shapes with .15 but can at .10.

Without a doubt this type of modeling is the most taxing on a system. I’d be somewhat surprised if any setup could union everything together and get AutoCAD to shell it properly, even at .10.

 

One procedure to break it down to smaller steps might be to CONVTOSOLID on the meshes, Run INTERFERE on two neighboring lumps and keep the resulting solid, SHELL at whatever thickness the operation will support, then SUBTRACT the interference solid from the shells.

That method would leave a bit of a step at the junction’s inside but that may not be a problem depending on what you are trying to do.

[basshead]

ok, thanks for your help SEANT