Adding Normals in OBJ exports

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jsreynaud
Posts: 1
Joined: Wed Feb 08, 2017 4:15 pm

Adding Normals in OBJ exports

Postby jsreynaud » Wed Feb 08, 2017 4:31 pm

Dear all,

A pull request to export normal in OBJ files format (Wavefront):
https://github.com/FreeCAD/FreeCAD/pull/509

Regards
toribio
Posts: 3
Joined: Wed Feb 08, 2017 7:46 pm

Re: Adding Normals in OBJ exports

Postby toribio » Wed Feb 08, 2017 7:48 pm

yes!!!!!!!, please
ian.rees
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Joined: Sun Jun 15, 2014 3:28 am
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Re: Adding Normals in OBJ exports

Postby ian.rees » Wed Feb 22, 2017 6:33 am

Out of curiosity (because I was looking at this for AMF export - https://freecadweb.org/tracker/view.php?id=608 ), what is the advantage in exporting the normals per-face in OBJ format?
toribio
Posts: 3
Joined: Wed Feb 08, 2017 7:46 pm

Re: Adding Normals in OBJ exports

Postby toribio » Tue Mar 28, 2017 2:34 pm

For me, when export cad parts to blender if the faces export the normal from surface avoid shading artifacts.

Image

In this image: top with normal's calculate from blender, bottom with normal's included from cad.

Basically the will let you see your objects in blender and others as you can see in your cad software, i mean, nor faceted or shading artifacts.

Cheers.
ian.rees
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Re: Adding Normals in OBJ exports

Postby ian.rees » Tue Mar 28, 2017 4:48 pm

toribio - is that car something you drew in FreeCAD?

The reason I'm asking, is that the normals this patch exports are per-facet, so they probably won't result in smoother shading. I think this patch is producing files that contain the same normals as what would be calculated by Blender, for example. -Ian-
toribio
Posts: 3
Joined: Wed Feb 08, 2017 7:46 pm

Re: Adding Normals in OBJ exports

Postby toribio » Wed Apr 19, 2017 6:28 pm

Hi, the car is an example of blender wiki, I don't know the internals for polygonal shading, lower image is as seen in the cad app and this is the data needed in blender, and any other app like blender. To add this kind of feature will bring a lot of users from the cad world, the most suitable app for this kind of work in this moment is http://moi3d.com/, but lack of 64 bits version, so big models are pretty impossible to export.

Cheers.