Attached Link: Try this ZTool on for kicks. Its a pig D1-5, 40k polys

Over the last 18 months I've been researching and teaching myself how to develop 3D character models suitable for rigging and rendering in popular consumer and developer rendering apps such as Daz, Poser, Messiah3d, Unity etc.  Maybe even Second life type games. Sounds like a good business fore the creative type.  Well its not that simple.  Beyond talentand moderate cost of entry, the single largest risk factor is making decisions based on assumption.  Especially when it comes to your pipeline.  Because nothing in this field is quite what it seems and there is no guartanmtee what you assemble for a pipeline that will produce acceptable results.  You cannot enter this field with the knowledge to understand what is needed to assemble a pipeline, it seems that its all trial and error.  Its a field dominated by an obsitnate monoply of products that have become a defacto standard.  Its cost is so unappealing that the inexperienced will attempt to waste their time with fringe an indepandant solutions.  WIthout the experience, the pipeline is developed using a serial, trial and error approach that takes years to develop, and only until then, exhausted and weary that the artist realizes that his tools are inadequate and will never produce results and either succombs to embrace the monoply or gets more pissed off and fights it...  That would be me.

So hereI sit with a dozen mesh projects that stall in a broken pipeline that cant seem produce results.  My issue is that I cant seem to export an .obj/.mtl that is suitable for my stated objective (importing into one of the rendering apps). The key features of the obj/mtl is that the structure of the mesh must be grouped, and retain its texture map. The texture map is composed of a composit of the groupings. The groupings are sub mes assemblies. In ZBrush this would be a sub tool made from poly group. In Hexagon its a mesh group.  In poser its a prop, composed of groupings of verticies.  I have a tool called SimLab 3D which allows me to asseble objects or divide objects by material name.  I have tried so many combinations and manuually editing teh MTL but am missing a key step. I believe its UV or texture verticymapping related but I cant define what I dont know.  If there a OBJ/MTL editing bible that I can refrence to figure how to stitch together my maps and meshes into something actually useable?? 

H E L P - Lost in ZBush http://dreamcutter.com/downloads/Abdomen.ZTL

Can you condense this down to an answerable question? Zb does UVs you might be better asking in that forum

Concise question:  What is the complete file structure of an .obj and refrencing .mtl for a structured (grouped) mesh and associated texture map? 

   Reason: I can't seem to find consistant refrence file examples to parse, and none of the configurations for the 3d tools I use seem to perform this properly.  Wikipedia on obj doesnt provide enough detail, example.  I need this to understand what I am fuindamentally doing wrong, and why my texture maps and not being applied to my welded grouped mesh.  I tried refrencing individual map (.jpg) for each group, and or an consolidted map in the MTL.  I am thinking there is no cooresponding vertice map to orient the texture map placement. Where in a MTL or OBJ is this information coded?

dreamcutter,

For every modeling/rendering program, there is another version of the OBJ format.  No two programs import/export the same OBJ format.

I am from the old days (mid-'90s when OBJ was only triangles and no UV mapping for most apps) where models were made of individual objects.  Each object has its own name in the scene.  Each object has its own material name.  Each object is UV mapped if it is using a texture image.  Since I only work on one model at a time in my modeling program, I don't need to group my objects.

Once a model is finished, I export each object of the model as its own OBJ file.  Then I import each OBJ file into my rendering program.  I then apply the texture images to each object (often times re-assigning its material name also).  I only group the objects together if I plan on moving the model around in my scene before rendering.

If I try to do this workflow any other way (using the same programs), it will take longer to fix issues and get my renders looking the way I want.

The Collada format fixed this OBJ problem for about three months until other programs began using Collada formats of their own.  Everyone is supported to be using the MAX format anyway. :)

You OBJ farmland model, for instance.  It's an old DAE format w/OBJ which my RAR extracted (thinking it was a zip which it was).  Anyway, the OBJ farmland model imported in modo 5 with self-lumination full on, and specularity full on.  Some extra material was included that did nothing, so I deleted it.

Someone not knowing how their program worked would have a hard time getting your farmland model looking right for rendering and would probably give up and look for another farmland to download from somewhere.  No, I have not imported your Ocean Vista Home model yet.  Anyway, this is just how modo 5 treats OBJ files.  Other programs may vary.

Another "fun" thing for new users to do is spend all day making a model of something (detailing it and painting it and wowing over how great it renders).  Then have them export their model as OBJ.  What the heck, right?

Now have them close their project and open a blank new one to model in and watch them import their OBJ they just exported.  What the....h!?

OBJ only works when one knows what its use is.

Ok.  The ocean vista home model.  Imported at OBJ into Hexagon and modo.  Both programs placed the house on its corner rotated 90 degrees and 45 degrees it seems.  modo cried about needing all the JPG textures that we not included.  Hexagon never thought to ask about them.

Since the model is free, I can't rightly cry about its craftsmanship.  :)

Shawn

Thanks for insightful replies.  

 RE: >>For every modeling/rendering program, there is another version of the OBJ format.  No two programs import/export the same OBJ format.<< this explains my fustration.  So I gather the various 3D apps look for the general OBJ structure and verticy addresses and then builds from there. What they take from the data they do, and append more metadata properties as needed in the MTL?  In other words they interpret what they can, processess and add value, and append thier app specific data as needed to the files.  To learn more rather than look at my modelers output I need to examine my render's desired INPUT. OK!  A direction....

Background being in CAD / Engineering I decided to give subd character modeling a try. Ultimately my objective being to learn to make "retail quality" 3D characters and props, in the mean time I get up to speed I use what I can to render still images for themed web sites.  With that goal, I figure I should aim to make open architecture and broad use to make the most of each model.  That result would be multi-resolution model & texture packs,  with collada and milkshape rigged versions. I'm thinking this would be the aim of most general content developers.  (?)

Is there a .DAE de-compiler (or source) that allows you to examine DAE file structure ?

an obj file can contain body part groups, material groups, and uv map info.  

part groups are "g" lines , material groups are "usemtl" lines and uv data is in the vt lines and F lines (face) definitions. 

There should be tutorials for moving objs from Poser to zbrush and back.

Poser may not recognise G lines directly, but you can use a PHI file to define the basic rigging of a figure (see the manual)

There are some  pipelines in use by "hobby" vindors but with all the combinations in use its hard to keep track of what will work best for you.

 

 

 

Thanks all.  I have been able to edit the mtl/obj set to properly group, hierarchy (PHI) and texture map the OBJ.  AT this point I am using seperate texture maps for each of the 31 groups. From what I have learned about OBJ/MTL render app compatability and editing, I think I can replace the individual texture files with a single merged texture map with VT indicies referencing the UV grouping regions.  Here sopem links that helped orient me

http://nendowingsmirai.yuku.com/topic/5556#.TyVwwVyCl5Y

 

http://www.blender.org/development/release-logs/blender-243/render-baking/

 

http://www.martinreddy.net/gfx/3d/OBJ.spec

Here is a partial mtl file.  The values allow diffuse, specular etc.

 

Note the map name has no path, so must be in the same folder as the obj and mtl file when imported.

 

newmtl 4_InnerMouth
Ns 100
Ka 0 0 0
Kd 1 1 1
Ks 0.501961 0.501961 0.501961
map_Kd V4SmplMouthM.jpg
newmtl 4_Gums
Ns 100
Ka 0 0 0
Kd 1 1 1
Ks 0 0 0
map_Kd V4SmplMouthM.jpg

 

try google for file specifications.

heres a website on obj specifications http://www.martinreddy.net/gfx/3d/OBJ.spec

 

Note that obj tends to be an exchange format which may limit what can be exported from the native application. For example Lightwave and 3dsmax both have attributes that dont transfer in an obj export.

 

For Poser my workflow is

1. create and group the item and save as a layered Lightwave file.

2. Collapse the layers and export as obj.

3. Import to Poser (or use phi for figure) .

4. Fix rigging, add morphs, set materials and save as a Poser prop or figure.

5. Fix the obj file reference in the pp2 or cr2 file.