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gap · 01-04-22, 11:21 AM

Yesterday I have had an insight into a couple of files, and I definitely see some problems.

This is a quick comparison of the two files:

Vertices (v)

As expected, 3D vertex coordinates are identical in number, order and value between the two files.

Texture vertices (vt)

For each file, there are more UV vertices than 3D vertices. This is expected because when you unwrap a closed surface for texturing it, you need to "cut" it in pieces so to make it as flat as possible and to avoid texture distortions. As a consequence texture vertices along the boundaries of "cropped" UV regions are duplicated.
There is a mismatch in number of texture vertices between the two files, the main object having a bigger number of UV coordinates than its UV2 copy. This is probably not good for TDW's importer, and it might be the consequence of me cutting further some UV regions when creating the main UV map from the AO one.

Vertex normals (vn)

Vertex normals are identical in number, order and value between the two files. Again, this was expected as the main and AO objects have the same 3D geometry.
There are more vertex normals than vertex coordinates. That should be the consequence of my models having hard edges in place. Since the vertices along those edges are considered as part of two or three surfaces (each pointing in its own direction) rather than one smooth surface, there is a need for the shared vertices to have more than one normal.
If I had removed hard edges before exporting the models, I am sure that the number of normals would have equated the number of vertices, and if I split the hard edges (as I did with the Blender exports), there would be as many vertices as the current number of normals.

Faces (f)

There is an equal number number of face definitions between the two files. Again, this is the direct consequence of the two objects being identical in their 3D geometry, thus having the same number of faces.
In a triangulated model each face definition is composed of three triplets of numbers, each triplet corresponding to one of the three vertices composing each face. Within each triplet, the first number should be the index to each of the 3D vertices connected to form a triangle; the central member of each triplet should be for texture vertices, and the third one for vertex normals.
- Between my two models, there is a partial mismatch in face order relative to the first (v) and third (vn) indices of each triplet. This mismatch might be caused by the fact that the main model has three materials assigned - one for the main texture, one for the railing and one for the rigging - whereas the AO model got only one material. Ungrouping materials in the AO model might have scrambled face order relative to the main model, since faces of the latter model are ordered on file depending on the material they use.
- There is a total mismatch of texture vertex indices, i.e. the second numbers in each triplet of face definitions. This mess might have been caused by the removal of "redundant" materials from the AO model (as above), but also by the cutting of some edges in the UV map of the main model (as explained before, there are more vt coordinates in the main model than there are in the AO model).

If Almagest could obviate to my mistakes, sorting out texture coordinates and faces in one click, that would be terrific. I realize that setting up the needed automated routines might be more complicated than it sounds though. Alternatively, I could try to manual edit my AO model in the hope to correct at least in part the problems above.
It that doesn't work, redoing the main UV mapping on the base of the AO model is still an option. That should not be a complicated task either. A little boring but not too complicated. For this particular task I think I would resort to Blender.
Blender's advantage is that, like Max, it supports multiple UV sets, and it got advanced and configurable shader setting. Very useful for previewing the combined effect of diffuse, specular, normal and AO maps. Unfortunately I am not as proficient in Blender as I am in Wings3D, but learning it better would be an investment for future projects.

01-04-22, 11:21 AM	#64
gap Navy Seal Join Date: Jan 2011 Location: CJ8937 Posts: 8,214 Downloads: 793 Uploads: 10	Lochinvar obj files, main and AO model Yesterday I have had an insight into a couple of files, and I definitely see some problems. This is a quick comparison of the two files: Vertices (v) As expected, 3D vertex coordinates are identical in number, order and value between the two files. Texture vertices (vt) For each file, there are more UV vertices than 3D vertices. This is expected because when you unwrap a closed surface for texturing it, you need to "cut" it in pieces so to make it as flat as possible and to avoid texture distortions. As a consequence texture vertices along the boundaries of "cropped" UV regions are duplicated. There is a mismatch in number of texture vertices between the two files, the main object having a bigger number of UV coordinates than its UV2 copy. This is probably not good for TDW's importer, and it might be the consequence of me cutting further some UV regions when creating the main UV map from the AO one. Vertex normals (vn) Vertex normals are identical in number, order and value between the two files. Again, this was expected as the main and AO objects have the same 3D geometry. There are more vertex normals than vertex coordinates. That should be the consequence of my models having hard edges in place. Since the vertices along those edges are considered as part of two or three surfaces (each pointing in its own direction) rather than one smooth surface, there is a need for the shared vertices to have more than one normal. If I had removed hard edges before exporting the models, I am sure that the number of normals would have equated the number of vertices, and if I split the hard edges (as I did with the Blender exports), there would be as many vertices as the current number of normals. Faces (f) There is an equal number number of face definitions between the two files. Again, this is the direct consequence of the two objects being identical in their 3D geometry, thus having the same number of faces. In a triangulated model each face definition is composed of three triplets of numbers, each triplet corresponding to one of the three vertices composing each face. Within each triplet, the first number should be the index to each of the 3D vertices connected to form a triangle; the central member of each triplet should be for texture vertices, and the third one for vertex normals. Between my two models, there is a partial mismatch in face order relative to the first (v) and third (vn) indices of each triplet. This mismatch might be caused by the fact that the main model has three materials assigned - one for the main texture, one for the railing and one for the rigging - whereas the AO model got only one material. Ungrouping materials in the AO model might have scrambled face order relative to the main model, since faces of the latter model are ordered on file depending on the material they use. There is a total mismatch of texture vertex indices, i.e. the second numbers in each triplet of face definitions. This mess might have been caused by the removal of "redundant" materials from the AO model (as above), but also by the cutting of some edges in the UV map of the main model (as explained before, there are more vt coordinates in the main model than there are in the AO model). If Almagest could obviate to my mistakes, sorting out texture coordinates and faces in one click, that would be terrific. I realize that setting up the needed automated routines might be more complicated than it sounds though. Alternatively, I could try to manual edit my AO model in the hope to correct at least in part the problems above. It that doesn't work, redoing the main UV mapping on the base of the AO model is still an option. That should not be a complicated task either. A little boring but not too complicated. For this particular task I think I would resort to Blender. Blender's advantage is that, like Max, it supports multiple UV sets, and it got advanced and configurable shader setting. Very useful for previewing the combined effect of diffuse, specular, normal and AO maps. Unfortunately I am not as proficient in Blender as I am in Wings3D, but learning it better would be an investment for future projects. __________________ _____________________ \|May the Force be with you!\| ...\/ Last edited by gap; 01-04-22 at 01:42 PM.