#70 OBJ importer does not load vertex normals

[BearT]

As discussed in the Help Forum [0] it seems that the OBJ loader exports vertex normals (field "nv") perfectly, but does not import them, when the previously exported OBJ file is loaded.

Error found in Meshlab rev.2902 using vcglib rev.3081.

[0] https://sourceforge.net/forum/forum.php?thread_id=2540435&forum_id=499533

[BearT]

I've tried to debug the obj importer and found the following. My meshlab exported obj contains about 2000 vertices more than it contains vertex normals. So it might be, that this is not a real importer bug, but either an exporter (unlikely) or a bug in normal estimation for point clouds.

I'll keep you updated in case I find sth. new.

[Nobody/Anonymous]

checked with a self created obj, which contains exactly the same number of normals and vertices. these aren't loaded either. from what I see in the code, the entries tagged with "vn" are parsed and stored, so it might be that the normals are lost later in the pipeline.

[Andrea Tagliasacchi]

I have the same issue. I load a mesh, then delete the faces completely and recompute the vertex normals using the plugin. When I export the oriented point cloud in OBJ format everything looks ok, but when I re-import it in the system, only the sample locations are imported, the orientations are gone.

This is a BIG problem, as when I want to perform reconstruction I want to import my normals, not to recompute them using Hoppe's heuristic!

[Andrea Tagliasacchi]

If you use ply files normals are imported correclty