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How smooth is smooth? [message #304] Thu, 24 July 2008 02:25 UTC Go to next message
avatar Sovereign  is currently offline Sovereign
Messages: 18
Registered: July 2008
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I use Rhino 3D 4 for my modeling. It can natively export to STL format, however this requires a NURBS to mesh conversion. The model I currently have up converted successfully, but there are obvious faces to the model despite me wanting it smooth.

The model is here: http://www.shapeways.com/model/1129/srv_01_survelliance_vess el.html

Will this print smoothly or should I mesh with more polygons?
Re: How smooth is smooth? [message #366 is a reply to message #304 ] Fri, 25 July 2008 21:30 UTC Go to previous messageGo to next message
avatar robert  is currently offline robert
Messages: 413
Registered: December 2007
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Hi Sovereign,

Nice model. Do you have more to show us? I would be very interested to see them!

I looked at your model. I would suggest to mesh with more polygons. Especially the body of the craft will not come out completely round. You will see some of the edges of the triangles.

You will happy to hear that in our next release of the portal there will be an option to make your model view-only.

Best regards,

Robert
Re: How smooth is smooth? [message #381 is a reply to message #304 ] Sat, 26 July 2008 15:49 UTC Go to previous messageGo to next message
avatar Sovereign  is currently offline Sovereign
Messages: 18
Registered: July 2008
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Apologies for the large images (900x600)... These were rendered in Rhino 3D (the application in which the model was designed).
http://img413.imageshack.us/img413/1761/viewfrontsb0.jpg
Front

http://img514.imageshack.us/img514/2220/viewperspectiveuc9.jpg
Perspective

http://img120.imageshack.us/img120/496/viewrearperspectivelz9.jpg
Rear Perspective

http://img301.imageshack.us/img301/9059/viewsidepc8.jpg
Side

http://img57.imageshack.us/img57/6886/viewtopvg5.jpg
Top

I did create a mesh with higher polygons, but the model was rejected and the system did not tell me why.

[Updated on: Sat, 26 July 2008 15:50 UTC]

Re: How smooth is smooth? [message #383 is a reply to message #381 ] Sat, 26 July 2008 21:35 UTC Go to previous messageGo to next message
avatar robert  is currently offline robert
Messages: 413
Registered: December 2007
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These renderings look fine to me. Are these from the same model? What is the polycount?

Best regards,

Robert
Re: How smooth is smooth? [message #384 is a reply to message #304 ] Sat, 26 July 2008 22:05 UTC Go to previous messageGo to next message
avatar Sovereign  is currently offline Sovereign
Messages: 18
Registered: July 2008
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Junior Member
3ds max 2009 x64 jammed trying to export to Autodesk Collada (DAE file). I am going to try to use the STL format, but I am going to send it to your support staff as I know most likely the automated system will reject it (most likely as being too big either in volume/dimension or filesize).

These renders are from 3ds max (mesh, not NURBS).
http://img95.imageshack.us/img95/4319/viewfronttg9.jpg
Front

http://img92.imageshack.us/img92/209/viewperspectivepl6.jpg
Perspective

http://img523.imageshack.us/img523/228/viewperspectiverearuz0.jpg
Rear Perspective

http://img301.imageshack.us/img301/2753/viewsideaz3.jpg
Side

http://img179.imageshack.us/img179/8489/viewtopwf1.jpg
Top

30,550 polygons and 19,033 verticies according to 3ds max. I only wish the front of the ship wasn't so pointy...

[Updated on: Sat, 26 July 2008 22:07 UTC]

Re: How smooth is smooth? [message #434 is a reply to message #384 ] Wed, 30 July 2008 19:33 UTC Go to previous messageGo to next message
avatar Barry_FM  is currently offline Barry_FM
Messages: 3
Registered: July 2008
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I just posted to another thread on a similar topic, hope this is helpful:

Standard rendering in 3ds Max (and to some extent all 3D renderers) has very little to do with the smoothness you will see in a final 3D printed model. Your expectations may not be met if you rely on the visual smoothness of a rendering.

To get a better idea of how the final model will look when printed...

A. Apply the Smoothing modifier to all objects and leave it with its default settings ( = Disable all smoothing groups in the modifier, and make sure nothing is checked such as Auto Smooth.) This effectively removes all renderable smoothing effects from the model.

B. Render the now flat surfaces at a very high resolution. Now you should be seeing a pretty good preview of the raw polygon shapes that make up your model's surface.

Even with these steps, the render will always be averaging the surface to make it into pixels so you still will have some very small 'fake' smoothing effect.
Re: How smooth is smooth? [message #546 is a reply to message #434 ] Mon, 04 August 2008 00:24 UTC Go to previous message
avatar Dalhimar  is currently offline Dalhimar
Messages: 173
Registered: August 2008
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Good work, Along with what barry said, using splines and nurbs is a fast way for the computer to calculate the mesh, though it dose give a very smooth initial look, it is doing that by using a special smoothing technique inherent to splines/nurbs. But once it is converted to a more standard type such as a "Mesh" or "Poly" inside of 3DS max and other programs, it reverts from the smoothed look caused by the spline/nurbs algorithm to the actual mesh, which contains much fewer polygons and vertices.
Just so that you can get a more accurate feel for the object before exporting, you can press "F4" in 3ds max to highlight the "Edges", or lines between each vertex.
Keep up the good work though.

 
   
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