topic Re: importing solid from AutoCad exploded into multiple element faces in 3ds Max Forum

importing solid from AutoCad exploded into multiple element faces

Anonymous — Thu, 17 Mar 2016 17:04:18 GMT

Hello,

I'm importing 3D Solids from AutoCAD into 3DS 2016-SP3 and some solids are a brought in as singal element and others are brought in as individual faces.

The attached .zip file includes a .dwg with a sample of what I'm importing and the attached sample.png shows the issue I'm experiencing. The round object is a single element, where as the triangle item's individual faces are elements. Note, that in AutoCAD these are both single 3D solid objects.

The import geometry settings I am using are as follows:

- Derive AutoCAD Primitives by: Layer, Blocks as Node Hierarchy, Split by Material

- Use scene material definitions

- Auto-Smooth adjacent faces

- Orient normals of adjacent faces consistently

Note - I can't change the Derive method do to dependencies of a MAXScript that looks for objects in the format of Layer:LayerName (which the selected method produces)

I'm really stuck why one solid is imported as expected and the other is what I would call exploded.

Any help or pointers in the right direction would be appreciated.

Thanks!

Re: importing solid from AutoCad exploded into multiple element faces

Anonymous — Thu, 17 Mar 2016 18:02:03 GMT

Sorry. I'm getting the same result. As I'm sure you already did, I tried importing it with all different types of settings. I even tried highlighting that all those faces and "Detach to Element" and it wouldn't take.

It's definitely strange that one object comes in as an element and the other comes in 'broken'. This indicates to me that it's not in the exporting .dwg settings but maybe how the original object was created?

Sorry I couldn't be more help but a least you know that you're not crazy. Good luck.

Re: importing solid from AutoCad exploded into multiple element faces

Anonymous — Thu, 17 Mar 2016 18:45:22 GMT

Thanks - I know when I use the Derive option: Entity, Blocks as Node Hierarchy - it imports them all as solids, but then the object names in the layers are 3dsolid and not Layer:LayerName.

Hoping someone can look at this and give me any other clues... but I appreciate knowing I'm not completely crazy.

Re: importing solid from AutoCad exploded into multiple element faces

PROH — Fri, 18 Mar 2016 10:00:41 GMT

Hi. Just tried to import your DWG file into Max2016, and I got the same result regarding the sub-object structure no matter if I import via "Entity, Blocks as Node Hierarchy" or "Layer, Blocks as Node Hierarchy". In both cases the one object is welded (watertight mesh) and the other is split into elements.

I think this is an old problem when importing solids: If the facecount is lower than "x" it will import as a watertight mesh, but if the facefount is higher than "x" it will be split (on sub-object level). What value "x" have in Max 2016 I dont know, but in your case the "watertight" object has 6726 faces (tris) and the "split" object has 26038 faces, so "x" must be somewhere inbetween those figures.

The way to deal with it, is to weld all vertices in the split mesh, making it watertight again (select object > activate "Vertex" sub-object level > select all vertices (control + A) > set a weld value (low) > press weld).

Another usefull tool in your case, is the "rename" tool (in the Tools menu). If you import by entity, you can easily rename all object on a layer at once to start with "Layer:LayerName".

Hope it helps

BTW - Please report this as a bug. The more reports the bigger chance it will be fixed.

Re: importing solid from AutoCad exploded into multiple element faces

darawork — Fri, 18 Mar 2016 12:28:04 GMT

I would have thought reducing the 'Maximum surface deviation for 3D solids' to .1 would fix this,

(Or perhaps more importantly, Setting the import weld threshold to a similar figure of .1)

sorry but I can't open my installation at the moment to check with the attached .zip.

Re: importing solid from AutoCad exploded into multiple element faces

PROH — Fri, 18 Mar 2016 13:23:15 GMT

"...Setting the import weld threshold to a similar figure of .1"

- "Weld nearby vertices" doesn't work when dealing with solids (they are per definition already welded).

"I would have thought reducing the 'Maximum surface deviation for 3D solids' to .1 would fix this"

- Lower numbers gives higher precision and therefore a higher facecount. Higher numbers gives lower precision and therefore lower facecount. Which number to use depends on the wanted quality + the degree of details being made in the given solid. In this case you need a pretty high quality to preserve the details.

Breaking up solids when importing to Max is clearly a BUG - but unfortunately not a new one 😞

Please log it.

Hope it helps

Re: importing solid from AutoCad exploded into multiple element faces

darawork — Fri, 18 Mar 2016 14:12:47 GMT

Report a bug page: http://download.autodesk.com/us/support/report_a_bug.html?SelProduct=3dsMax

Re: importing solid from AutoCad exploded into multiple element faces

Anonymous — Fri, 18 Mar 2016 14:35:11 GMT

Thanks Proh and Dara for your input -

Proh, you're correct - I've tried higher and lower numbers on the surface deviation without success.

I'm reporting the bug as suggested. Thanks again!