Hi All,
I have been given this 3dm file, it is a well detailed and lovely Palm that I would like to add it to my scene in MOI. I have attached the file. I can open it with Rhino Evaluation and see the content. However in MOI I can open the file but the scene is empty, I can not see the content.
Can someone help me with this?
Thanks,
Lars

Hi Lars - your 3DM file there only contains polygon mesh objects in it and no NURBS objects.

Rhino is set up to work on a variety of different kinds of data, while MoI is only focused on one particular kind of data.

If you select the object in Rhino and use the "What" command you'll see it is reported as a "mesh" object and not as a surface or polysurface type object - that's why it is not being read into MoI, because MoI does not work with polygon mesh data at modeling time, it only generates that kind of data for export.

Polygon mesh data is a pretty different type of 3D structured data than NURBS data - normally for working with that type of data you would want to load it into a polygon mesh oriented program, something like Cinema4D, Modo, etc... - usually it's the more animation and rendering type programs that use that type of data.

- Michael

Thank you Michael,

I missed that. I need to find a way to convert polygon mesh objects to nurbs objects, providing we can do it.

Lars

Hi Lars, it's quite difficult to do a good quality conversion from polygons to NURBS objects.

Polygon data has everything all smashed up into little planar faceted bits.

NURBS objects has things structured as large smooth spline surfaces.

It's possible to turn a NURBS object into polygon mesh data by taking the big smooth NURBS surfaces and dicing them up into little pieces. Think of this as similar to making applesauce by taking apples and smashing them up.

But it's quite difficult to go the reverse way and try to reform large surfaces from already diced up data - that's sort of like trying to start with applesauce and then trying to reform whole apples again from it.

There are some special types of reverse engineering tools that do that kind of stuff but they're complex and expensive. See here for some links to some of those:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4829.3
http://moi3d.com/forum/index.php?webtag=MOI&msg=1901.9


If your object has a relatively low polygon count, it can be possible to convert it by making one trimmed planar NURBS surface for every polygon face - to do that use the Obj to 3DM wireframe converter as described here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=5135.5

However, that kind of "one individual little trimmed NURBS surface for every polygon face" type conversion won't work very well with heavier polygon counts because NURBS objects are not intended to be made up of so many separate little fragmented pieces, they're intended to have bigger pieces of the model made up of large smooth surface patches. There is some more overhead to the way NURBS represent surfaces and trims so having a zillion little surfaces creates a very heavyweight object in that pseudo-NURBS form ("pseudo" because it's all faceted and not actually smooth). See here for more description on that:
http://moi3d.com/forum/index.php?webtag=MOI&msg=5135.13


So basically it is technically possible to do that conversion but it's often not a good idea. Usually the conversion only goes the other direction, from NURBS to polygons.


- Michael