Importing .obj as separate parts

Hi all :slight_smile:

I’m busy on a detailed model of the Cutty Sark in Hexagon, but want to complete it in Blender because Hexagon, being 32 bits, starts getting real slow after 50K polys and there’s still a lot more to come.

In Hexagon, I have over 100 separate meshes in groups and exported it as such. Blender imports as a single object, with all the “sub-objects” listed in the outliner, but they are not individually selectable - I want to put them in groups on separate layers to make further modelling easier.

The separate meshes are listed as vertex groups, so can be selected that way, or I can select them with L and separate them into their components. Another method would be to export from Hexagon in parts. Any of these methods is going to be a lot of work, so I’d like to know whether there is a method of importing the model as it was exported, so that the parts show up as separate meshes in Blender.

Then, looking ahead for after completion, I will be distributing the finished model in various formats, including .obj. I’ll be using Cycles textures - how would I go about preserving the shading? In tests I have done on simple models, I found that importing into Carrara, I have to bring in the textures, but can’t find where Blender stores them. Hexagon, for instance, stores textures in the same folder as the exported ,obj.

OBJ import export is super finicky.

  • first thing to plan for is weather you need the same Vertex Order once you export it back from Blender (for blendShapes and such). If so, as far as I know, you have to import and export objects one at the time with KeepVertexOrder in OBJ Export Settings

If you don’t need the same Vertex Order:

  • Make sure in your Host App all objects have unique names
  • Import to Blender using the default Split option with Object and Group checked

Try using FBX, it has many advantages over OBJ (even when considering just model/mesh export/imports), like preserving pivot points and transforms. Makes it a hell of a lot easier if those are preserved.

As for the texture files, a neat trick is to pack them into the blend file. You then open that file and unpack it choosing ‘Write files to current directory’. This will create a Textures folder with all used files in there. Very handy when working on different systems with different folder structures.

You will find packing commands:
File > External Data

Thanks a lot for your advice :slight_smile: I have been using the alternative settings since starting with Blender on other advice - the default works fine for what I want. Hexagon unfortunately doesn’t do fbx.

The times I’ve tried importing figures with armatures from Daz Studio and Carrara have been a disaster and I’ve tried using every setting in the Autodesk fbx converter. There are so many flavours of fbx and I’ve not been able to find which one suits Blender. FBX exports from Blender work fine in Carrara, but not the other way round.

Cheers:)

Checking to see whether I’m understanding the workflow to save materials externally - made a cube, gave it simple colours (Cycles), saved, packed all in .blend, saved, closed. Opened and went to External Data to unpack and found both pack and unpack options greyed out. what part of these steps am I missing?

Attachments


If you don’t use any image textures on the mesh and/or the environment at all - what external data is there to pack/unpack?
Other than that: AFAIK the OBJ importer/exporter can’t read/write node based materials. So, only for BI material data will get exported/imported.

Thank you, I think I have it now :slight_smile: The pack/unpack only works with externally-sourced image textures. To be able to save as .obj with retention of internally-generated materials, I must use BI and not Cycles. So I can set up the materials in BI, export as .obj, then convert materials to cycles for the .blend version?

Would baking Cycles mats not work for an .obj version?

Yeah, of course you could bake Cycles materials to textures, apply them in BI and then export to OBJ.

Yes - that method works nicely, thank you guys for your assistance :slight_smile: