No holes/intersection, still cannot convert to solid

[knattagh]

I am using AutoCAD 2013 and am not able to make a solid of this mesh that attached. Making a solid of the mesh is just one step, my final goal is to make a shell of the mesh, for example if the mesh was of someones face then that person could wear the shell that I intend to print as a mask of some that I can specify.

 

 

Ill start off by saying that I used netfabb studio to check for holes in my mesh and found none. I used meshlab to check for intersection and also found none.

 

 

I could not fit the dwg file on this so I just put the dxf. If you want another copy let me know and I can email it or something else.

 

 

My plan is to:

 

1. Convert the mesh to a surface, leaving me with a surface with thousands of faces.

2. Then I smooth those faces out leaving me with 1 face

3. I could then thicken my object and be complete.

 

I could also

 

1. convert to solid

2. thicken

3. derive the old, smaller, part

4. subtract out the old smaller part

 

 

Here is what is going on when I try:

 

I cannot convert the dwg to a surface or a solid so I tried the dxf. The dxf was converted to a surface but not a solid. I cannot smooth the edges for some reason.

 

Any idea which plan works best if at all? And if so, any advice on getying passed some of my problems would be much appreciated.

 

Thanks

Khash

bladder(2).dxf

[ReMark]

I thought that JD Mather would have jumped all over this one as it is right up his alley. Maybe he was helping himself to a second cup of spiked eggnog. Let's give it a *bump* and see what happens.

[JD Mather]

1. Convert the mesh to a surface, leaving me with a surface with thousands of faces.

2. Then I smooth those faces out leaving me with 1 face

 

Contradictory terms in your problem description.

Surfaces are infinitely thin and have no volume.

Solids have Faces. (I think there is a good explanation in one of the papers linked in my signature).

 

The process (if it is going to work) would be to smooth the surfaces, convert to solid and then shell. (based on you description of a mask - I assume there will be some trimming (slice) involved as well). There is no possible way to make this with only 1 face in AutoCAD.

 

I think there might have been a topic on this at AU this year, did you find the document at http://au.autodesk.com ? (I haven't looked at it yet, so I don't know if it covers your problem situation.)

[knattagh]

I just looked at all of the courses in the 2012 and none of them had mesh in their titles. I googled it and got the link below, it seems like I should download visual LISP according to think article.

 

https://sites.google.com/site/togoresconsulting/home/lispyourmeshtoshape

 

About your plan,

 

I believe shelling wont do what I need because I need the object to "thicken outwards" if I may. Shelling seems to effectively be thickening a surface inwards.

 

When you say I cannot make 1 face with autoCAD, what about "smooth optimized" ?

 

Also, what about thickening and offset options?

 

 

Thanks

-Khash

[JD Mather]

I will try to post an example later today or early next week (bump this to the top if I don't).

 

Shell IS a thicken operation. You can shell towards the inside or outside.

[JD Mather]

OK, here is the example file. Mesh.dwg

Left to right

Orignal>Smooth More>Smooth more a second time>Smooth Optimized-Delobj=1>Convert to Solid

 

Notice the final solid has several Faces - I changed the color of some faces with the Color Faces command.

 

[knattagh]

Thanks for the example!

 

I am not sure what the Smooth Optimized-Delobj=1 means. What I did was the following:

 

original>smooth more>smooth more again>Smooth Optimized > convert to solid and the last step, convert to solid, does not work.

[ReMark]

Maybe it's time you gave JDM's method a try then.

[knattagh]

Yes ReMark I agree and would love to try JDM's method but I'm not familiar with "Smooth Optimized-Delobj=1"

 

I am however familiar with

"smooth optimized"

 

Could you possibly help me understand how carry out

"Smooth Optimized-Delobj=1"

 

Thanks

-Khash

[ReMark]

Isn't DELOBJ a system variable in AutoCAD?

[knattagh]

Yes the following link gives some information about it but it still puzzles me

 

http://docs.autodesk.com/AMECH_PP/2013/ENU/index.html?url=filesACD/GUID-CB64587F-611E-441E-AB07-14B415BF535F.htm,topicNumber=ACDd30e428560

 

I tried typing in SmoothOptimized-Delobj=1 into the command bar to no avail.

[ReMark]

What is the Delobj variable currently set to?

[JD Mather]

I tried typing in SmoothOptimized-Delobj=1 into the command bar to no avail.

 

I meant to type Smooth Optimized with Delobj set = 1 and then Convert to Solid.

This is so that you don't have the surface body and the solid body overtop of each other.

Another option would be to move one or the other to another layer and then turn off the surface layer.

[knattagh]

Oh thanks I get it now. ReMark I had it on DelObj = 3 and just changed it to 1.

 

I'm pretty sure i followed your steps JDM. I then cut the face > pressed the shell button > selected the solid > selected the big face produced by the cut > entered some thickness > and now my screen looks like the pic I attached and I am not sure what to do.

 

[JD Mather]

Now we enter a second - more difficult phase of the problem.

Imagine that you have a circle of R1mm and you try to offset (similar to thicken) towards the inside of the radius a distance of R1.1 or and distance greater than 1mm. What is the solution?

 

In 3D the curvature of a face takes more analysis to find where a problem of this type occures. To find the problem locations it is usefull to go back to surfaces and Thicken one-by-one. The process and solutions is a bit beyond a web forum discussion.

 

If you exapand your command line or hit F2 you should see an error message something like - could not find solution at vertex.....

[knattagh]

I would imagine it would be impossible to offset by any distance greater than 1mm, but I am not sure I follow your logic since I am trying to thicken out.

 

The error message is "could not offset surface as requested"

 

Should I stop posting about this?

 

Thanks

Khash

[JD Mather]

... but I am not sure I follow your logic since I am trying to thicken out.

Khash

 

That is exactly why I am not continuing the discussion - the topic should be covered in a class.

But in 3D surface modeling there is curvature in any direction. Even though you are trying to thicken out you might be attempting to "thicken" a curve beyond zero curvature. Look at the example I posted. There is both "convex" and "concave" curvature. If you run Curvature Analysis you might get a better picture of the curvature.

I would guess about about 3 yrs of effort to get a good handle on the topic.

Not sure I have a handle yet.........

[knattagh]

Ok I see. Well I appreciate your help

 

I have an idea about some way to do it on inventor, I should probably start a new thread on the inventor forum so Ill do that

 

Thank you!!

Khash

[JD Mather]

Open the dwg file in Inventor (set Options to Import) and give it a bit of work there - both as an attempt to shell the solid, and if that doesn't work then individual faces (of the smoothed, simplified model as demonstrated with the AutoCAD example).