Convert 3ds to solidpart in SW

How to convert 3ds from 3DMax to solidpart in SW and make it smooth? The convertion with the ShapeWorks program makes it look made of polygons.

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Momentary
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How to convert 3ds from 3DMax to solidpart in SW and make it smooth? The convertion with the ShapeWorks program makes it look made of polygons.

Reply to
Momentary

That's because that's all you have in 3DS, polygons. The smoothness, in 3DS, is achieved graphically. A 3DS file is equal to the display list in SW, just a bunch of shaded triangles. There is no mathematically exact data.

You can't really make something from nothing. There are a couple of programs that "claim" they can drape NURBS surfaces over a 3DS polymesh, but you'll end up with an approximation of an approximation. OK if you're just using objects for a rendering scene. Terrible (and not worth the time and effort) if you're using it for product design.

Mark

Reply to
MM

3ds meshes have smoothing groups that define sets of polygons that are a continuous surface. I find a lot of .3ds files that don't have smoothing groups defined, so you end up with an entire mesh that looks tesselated. I don't know if ShapeWorks will read in the smoothing groups (I am usually going out of SW into 3ds max), but if you want to send me the .3ds file I could at least check to see if there are smoothing groups defined.

Joel

Joel Howe

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Reply to
jhowe

Smoothing groups is a propriatery "algorithm" inside 3DS, not a graphical "object"

Some things, like lights and textures, are tranportable to other animation/rendering programs, like Maya, but not SW.

In this respect SW is simple. You have hard exact geometry that contains real mathematically defined curves and faces. This is tesselated (diplay list) and the tesselation is smoothed autmatically by OpenGL. The underlying

3D object is really smooth

With 3DS you have tesselated objects to which you apply smoothing algorithms to make the object "appear" smooth. The underlying object is tesselated. This is usually OK because the intent is to create animations or renderings. The program "is not" a design tool.

SW reads in "Geometry", not attributes. If the geometry exsists in the originating system as B-rep solids (STEP, X_B, SAT, or IGES-186), then that's what you get.

If it exists as a polymesh, (VRML, STL, etc) then that's what you get.

We've had Max as long as we've had Solidworks. The only usefull direction is SW to Max for special renderings or animations. Max to SW is a complete wast of time and energy. The only solid design product I've ever used that can read in 3DS, with all the attributes, Is Iron CAD. Even then, you were very limited as to what you could actually do with the data. With Solidworks, it's like apples and oranges.

Regards

Mark

Reply to
Mark Mossberg

Mark,

Everything that you write is correct, but doesn't really answer the person's question.

My thought was: Since SolidWorks does have to tesselate a model, or convert it to a polygonal mesh, for display on the on the screen, then it does make sense that it has some capability to interpret what 3ds max calls smoothing groups. Assuming this is true, then maybe ShapeWorks can keep track of this. Smoothing is ubiquitous in all polygonal modelers, so maybe a properly smoothed model will help improve the display of the object in SW. It is also safe to assume that PhotoWorks (which is really mental ray) is creating a polygonal mesh to render and would recognize smoothing.

I think you are correct, assuming someone has access to 3ds max. If they do not, I have see plenty of situations where you might want to bring 3ds objects into SW for reference. Human models for ergonomics/medical devices, automobile exteriors for showing placement of system components, etc. You are right that the 3ds files or any other tesselated formats are not really usable for actual design parts, but they are great for reference.

Reply to
jhowe

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