How do I export an OBJ from Blender to import with separate parts in DS?

CrissieB

I'm using Blender to design a four-room basement set for DAZ Studio. I have the basic architecture -- floor, exterior and interior walls, ceiling, and stairwell -- fiinished, including UV maps and material zones. I want to import that architecture into DS as a figure with each object as a bone, so users can hide parts of the set as needed while working on a scene.

I've done this before from Hexagon, and it was no problem. I simply exported the file as an obj, opened DS, opened the Figure Setup pane, left-clicked to add geometry, selected the obj file, and the component objects were there, ready to be assigned as bones.

Alas, when I did that from Blender, the entire set came in as a single object.

I've assigned each Blender object to a vertex group, although I used the same names for the object and the vertex group. Is that the problem?

Also, the Blender objects share materials (e.g.: each utility room wall uses the same UtilityRoomWall material) so users don't have to change the texture for each wall. Could that be the problem?

Thank you for your help. :-)

Richard Haseltine

I seem to recall there are some subtkle wrinkles in getting groups from Blender, though I an't recall the details. Whata re your export settings in Blender?

bobswrench

Here's a blog which describes exactly what you're asking for.  You'll want to save this since it's been around for a while and stuff does tend to disappear.

https://blendertodaz.wordpress.com/

Bob

CrissieB

@Richard Here are my Blender export settings, with (+) indicating checked and (-) indicating not-checked:

Forward (Z Forward), Up (Y Up), Selection Only (-), Animation (-), Apply Modifiers (+), Include Edges (+), Smooth Groups (-), Bitflag Smooth Groups (-), Write Normals (+), Include UVs (+), Write Materials (+), Triangulate Faces (-), Write Nurbs (-), Polygroups (-), Objects as OBJ Objects (+), Objects as OBJ Groups (-), Material Groups (-), Keep Vertex Order (-), Scale (100), Path Mode (Auto). I set the scale to 100 because Blender's unit is 1m while DAZ's unit is 1cm.

@bobswrench He is assigning two vertex groups to a single object, a cube that he divides into a chest. My scene has 11 objects: Ceiling, Floor, 4 exterior walls (EastExtWall, NorthExtWall, SouthExtWall, WestExtWall), 3 interior walls (MainSecUtilIntWall, SecUtilLavIntWall, UtilLavIntWall), Stairwell, and a doorway filler (MainSecNoDoor) in case users don't want a door between the Main and Second rooms. Each object is assigned to its own vertex group with the same name.

Do I need to Join all 11 objects into a single object (say, BasementSet) with the vertex groups then 'separating' each component? If so, will the Join operation wipe out my current UV maps, material assignments, and vertex groups?

CrissieB

Well, I tried joining all 11 objects (floor, walls, ceiling, stairwell) into a single BasementSet object, with each part in its own vertex group. Joining them overlaid their UV maps, which is a real mess. More's the point, a single object with 11 vertex groups came through exactly the same as 11 objects, each with its own vertex group ... as a single object with no component parts that I could separate into bones. So that's not the solution.

bobswrench

Hmmmm,

That doesn't bode well for my upcoming experiments.  I've done something similar going from Blender to Poser and it works perfectly.  I'd like to try it in Daz3D next which is why I directed you to the blog I'd found.  Jack Tomalin has a tutorial which details this process but his site is getting a re-design rightt now.

When exporting for Poser I use the following,

CrissieB

Those settings worked perfectly! :-)

I didn't need to join the Blender objects. Each object having its own vertex group worked fine. Also, I didn't check the Selection Only, because I wanted all 11 objects to come through. With (+) meaning checked and (-) meaning unchecked, my settings were:

Forward (Z Forward), Up (Y Up), Selection Only (-), Animation (-), Apply Modifiers (+), Include Edges (-), Smooth Groups (-), Bitflag Smooth Groups (-), Write Normals (-), Include UVs (+), Write Materials (+), Triangulate Faces (-), Write Nurbs (-), Polygroups (-), Objects as OBJ Objects (-), Objects as OBJ Groups (+), Material Groups (-), Keep Vertex Order (-), Scale (100.00), Path Mode (Auto).

Again, the Scale of 100 is because Blender's unit is 1m and DAZ's unit is 1cm.

Thank you!

bobswrench

Those settings worked perfectly! :-)

Really?  That's great.  I'll jot that down in my tutorial.  I have one for going from Blender to Poser and am working on another to go to Daz3D.

Glad to have helped.

Bob

CrissieB

@bobswrench You'll need to change those export settings to ensure DAZ gets the normals correct on all faces. Here are the settings I used, with (+) meaning checked and (-) meaning unchecked:

Forward (Z Forward), Up (Y Up), Selection Only (-), Animation (-), Apply Modifiers (+), Include Edges (+), Smooth Groups (-), Bitflag Smooth Groups (-), Write Normals (+), Include UVs (+), Write Materials (+), Triangulate Faces (-), Write Nurbs (-), Polygroups (-), Objects as OBJ Objects (-), Objects as OBJ Groups (+), Material Groups (-), Keep Vertex Order (-), Scale (100.00), Path Mode (Auto).

Crissie

 

bobswrench

Hmmm,

From a discussion over at Rendo some time ago it was revealed that Poser does NOT see normal information in imported obj's.  It made it's own normal orientation from the 'winding order' (no idea what this is) of the polygons.  Are you saying that Studio DOES import the normal orientation?  I've had parts of imported items show up blank in Poser and fixed it by flipping the normals in Blender then re-importing the item. 

Cool, another difference to note.  While I work (mostly) in Daz, I keep everything I make Poser compatible to make sharing easier.

Thanks,

Bob

CrissieB

Yes, DAZ will import the normals if you include them in the export. When I first tried to render my Basement set, without the normals included in the obj, DAZ had reversed at least two normals that I could see in my camera angle. Part of one wall and the main room floor came up gray. (Oddly, the other floors -- part of the same plane object -- and the other parts of that same wall were fine.) I re-exported with Write Normals checked, and that solved the problem:

This is Marie, dancing in the main room of the Basement set. The second room is the wood-paneled one in the back left. The utility room is in the right background, with the lavatory behind that.

I modeled the ceiling light fixture prop in Hexagon. It provides all of the main room lighting, but not from the tube light you see inside the frosted glass shell. There is only one tube, wrapped all the way around, divided by mounting brackets in the shell. That tube is just bright enough to light the shell itself.

The scene is lighted by a second, invisible emitter. It's the same shape as the glass shell, but with a 1cm larger radius. It has the same emission color and temperature as the fluorescent tube, so it looks as if the light comes from what you see. It's much brighter, enough to light the scene for rendering, and because it's invisible you don't get any harsh glare from the crushed silk wallpaper.

Obviously, I haven't added the staircase, doors, baseboards, chair rails, cornices, light switches, wall outlets, or any lavatory fixtures yet. Those will all be separate props. I don't plan to model common furniture that users could download for free from cg-sharing sites, but I will model the unique props for the set. I'll also do materials for three setups:

(1) A family basement with the main room a rec room, the second room a computer/craft room, the utility room a laundry room, and a lavatory. This scene shows that layout.

(2) A private casino club with the main room a cardroom, the second room a sauna, the utility room a coatroom, and a lavatory. The set's basic architecture includes another version of the wall behind Marie, with no doorway between the main and second rooms. That wall is hidden for this scene.

(3) A condo/apartment fitness center with the main room having cardio and weight machines, the second room for yoga-jazzercize, cubby lockers in the utility room, and a lavatory.

Lots of work left to do....