Still I need to understand something…
But I learned the following points from importing work…
- Before importing pmx, get rid of all joints and rigid bodies. You don’t need them and to be simple work in blender.
- Before importing pmx, you had better change Japanese material’s name to English. You could edit in blender but sometime uploading failed to secondlife (parse error).
- mmd_tools helps us for importing and editing pmx. We should add this on blender. https://github.com/sugiany/blender_mmd_tools
- Avastar helps not only secondlife born(armature) parenting but also exporting collada. If you would like to separate object and make seamless among them, need “Weld Edge Normals” option in Avastar exporter. About weld edge normals, please see this post. http://meshdolls.blogspot.jp/2013/04/avastar-weld-edge-normals.html
- One object should have 8 materials or less. You need to separate pmx mesh by “materials” with using mmd_tools “Separate by materials” in tool shelf. “Separate by materials” keeps armature modifier, materials, vertex group and shapekey information. No collapse meshes by shapekey (morph) incorrect data by this approach.
- In editing, you should always pay attention on shapekey. Basis! Basis! Basis!
- When you want to separate mesh more, don’t delete vertices. Create new material, assign vertices, copy material data from original to new one and “Separate by materials” in mmd_tools. If you just want to delete, you don’t need to copy material data to new one.
- When you want to copy mesh, Avastar custom mesh tool “Freeze Mesh” helps you. Getting rid of shapkeys but keeping morphed mesh, armature modifier, material (same name of original) and vertex group. To make facial expressions mesh, this freeze mesh is useful.
- When joining meshes to one, you should consider its materials naming. If you would like them to be different “side” in secondlife, you should differentiate material’s name. Don’t change its name directly. Make new material, assign all vertices and copy material’s data from original to new one.
- “Apply scale and rotation” – Avastar exporter does it by option but when pmx model scale and size changed for avastar or skelton base, apply them.
- Make T-Pose (rest pose) by using pmx born(armature) pose mode. You need to add armature modifier more and apply original one. Please see this page for how-to. http://nixart.wordpress.com/2013/03/28/modifying-the-rest-pose-in-blender/
- PMX model has many “doubles” vertices. Mesh tools [Remove] [Remove Doubles] helps you reducing vertex count and getting rid of line on surface in the same material.
- PMX model doesn’t have lining faces backing for clothes therefore you should duplicate faces and invert normals of them. Please see this post. http://meshdolls.blogspot.jp/2013/01/making-liner-normals-inside.html
- Secondlife doesn’t support custom shapekey (morphing). We can’t export facial expressions by shapekeys to secondlife. So prepare facial expression meshes (materials) and control transparency by LSL(Linden Script Language). Please see this post. http://meshdolls.blogspot.jp/2013/04/avastar-weld-edge-normals.html
- Modify secondlife born skeleton or avastar armature. Move armatures to same position of PMX armature. head, neck, collars, shoulders, elbows, wrists, chest, torso, pelvis, hips, knees and ankles are key armature points. Avastar armature is so special therefore see this video. https://www.youtube.com/watch?v=mL4X1AlMtVU
- Don’t use Avastar parent tool [Rigging] [with Weight Copy] nor blender parent [With automatic weight]. PMX model already has weight data. For parenting to armature, you had better use blender parenting(Ctrl+P) and [With empty groups].
- Modifier “Vertex Weight Mix” can add PMX vertex group weight to secondlife armature vertex group. Especially for body parts, you can get so excellent weight from original model mesh/vertex groups.
- In uploading collada file to secondlife, use [with joint position] option for body, especially including elbows and knees. Because secondlife armature’s joint positions are changed by modified for PMX born style.
- Some parts should not be used the above [with joint position] option in uploading collada. For example, changing side’s alpha scripted objects like “face and eye”. I don’t know why but we see flick model in-world.
- About image (picture) file, you would need to convert files to JPEG. TGA and PNG has alpha channel and secondlife sometimes can’t handle them correctly.
In addition, it takes over 2 years to understand/learn the above by try and errors. Still I feel I don’t know blender and 3DCG thoroughly. I really appreciate that Avastar Gaia Clary youtube channel always gives me many hints https://www.youtube.com/user/gaiaclary and so many blender tutorial videos and blog posts also help me.
Thanks, Enjoy and good luck
