Can you show the obj file to someone to check if it is valid? For example for cloth simulation.
Hello Dismine. I"ve downloaded the object file, and tried it out in Blender 2.76b. The object will probably work in 3d studio max as a draped cloth, but not in Blender or Maya or Modo. I’m going to try MeshLab to see if I can get the quads-only object that I need.
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All i need to know is valid the file or not. Because i am ready to start working with quad mesh.
And here is your answer. Yes, it is read as-is for draping; it will require quads for folding during an animation.
I think that means it’s a valid .obj file.
Online 3D Model Converter converted your mesh.obj file into .json and .stl files. It accepted your mesh.obj file without error messages. mesh.json (252.5 KB) mesh.stl (338.5 KB)
Yes. I had to re-calculate the normals so that they all faced outward, then I weight-painted it as thin silk, Such a mesh will work as-is for things like bedspreads and drapes; for animation, however, it will need a quad conversion with as many edge-loops as possible. Armatures (rigs) like edge loops.
ok should the mesh algorithm do this?
This will make the resulting garment look good. The pieces that are sewn together can’t show gaps when the character moves.
Recalculation of normals is best done in the 3d suite; as every major 3d app has its own approach. Usually, there is always some polygon editing to do, so I would say the mesh algorithm need not include this.
Edge loops are important when considering how accurate the UV map needs to be (how little distortion) when an animation is running. Consider how a plaid will look if the UV map is stretched too much. I"m thinking that Valentina will want to have the animations look as realistic as possible. So, more edge loops under the arms, behind the knees, along the hip crest, for example.
Can you give me more info what should be done? I simply not very deeply familiar with 3D.
One more thing to ask. Should length of edge in each piece be the same? Or i can generate meshes separately for each piece.
There are two things to consider in your coding: (1) a least-mean-squares approach to the mesh, so that the UV (texture) map will have a minimum amount of distortion. Think of this in terms of what a plaid shirt would look like during an animation. (2) only break the first rule when it comes to joints with a high degree of articulation, the armpits and the hips. Elbows and knees need a mesh that has bigger (broader) polygons at the point of elbows and knees, and narrower in the crooks of the elbows and knees. And finally–and this can only be suggestion, not a rule–edge loops whenever possible. Why? An armature can move a circle (any primitive object) without distortion, but the more organic a shape is, the less predictable the outcome. Edge loops are best possible geometric solution. HTH.
Having used Marvelous Designer for a year–and seeing its strengths and weaknesses–I would suggest generating meshes separately, as each 3d suite will have its own algorithms for stitching. Blender users makes a big point about this new plugin. So that should make your job easier. HTH
Unfortunately your answer does not answer on my question.
Probably i don’t get something. I will try to explain. Currently i export only vertices and faces (triangles), but you said you need normal as well. I saw in obj format description about that part, but because i don’t know how to use it and how to calculate i skipped that part.
You do not need to worry about normals. Recalculation of normals during mesh editing (there’s always a polygon or two that needs tweaking) is built in to all the major 3d suites (which I have already noted, though you can add Cinema 4d). The feature beyond vertices and triangles is the planning necessary for edge loops near or on the stitches; this is usually done by having code that limits the number of branches off the nodal vertex. For example in Makehuman MakeClothes, a clothing mesh can have no more than 6 (six) branches, if more, MakeClothes will throw an error. The limitation of MakeClothes is that it isn’t production-ready; the mesh is laid out on a rectangular XYZ (3d) grid. Marvelous Designer does this better, by having ‘diamonds’ that are rotating at angles off the Y plane, but they cut corners by using triangles. What is needed is code that uses only quads, but rotates them off the XYZ grid.
Here’s an example of those ‘twisted diamonds’ as I like to call them, with one level of subsurface subdivision:
And finally, I’ve only used Blender and Marvelous Designer as an artist. I discovered that I could get perfect flow from Makehuman through Blender to Marvelous Designer in Collada format (because of MD compliance with OpenCollada). So…I only know Wavefront objects; I haven’t used anything with DXF format in over a decade. Mostly I’m working on martial arts animations, to the point of going the gym (which I manage) and trying out the moves themselves.
Another question. As i understood from your words some parts of mesh need thickening? That’s a problem because my algorithm don’t like that. Do you really need that level of accuracy? Because now i can provide only uniform mesh. mesh.obj (830.8 KB)
We have two workflows which have some similarities:
DXF creates separate layers for seamlines, seam allowances, passmarks, internal lines, grainlines, text labels.
The OBJ only includes the seamlines, passmarks, and internal lines.
So, can we develop the OBJ export without having to generate layers first?
Can the OBJ export code select the seamlines and internal lines without seamallowances, and include the passmarks for seam matching?
We’re certainly communicating from different worlds! 
What I mean is that where the objects will join during stitching should yield an edge loop if possible. This makes animation much easier.
So, no, your mesh does not need to be thicker; instead you have to plan were the edge loops will need to be.
The best explanation will be by way of illustration. I did a tutorial on the Makehuman site called “Rigging and Weight Painting the Perfect Punch”. This move causes terrific distortions in the mesh, if not planned for. I solved the problem by adding an edge loop (see the second screen shot).
Yes to all these questions. I haven’t used the Blender stitching plugin much (only once, actually), so we’d have to try a few examples. I would suggest a nurse’s uniform of t-shirt and slacks for starters.