Export script for instanced meshes to Unreal from Blender (FBX + T3D)

export_t3d.py

"""
Work in progress. It works, but no file output options and T3D currently prints to console
references:
https://forums.unrealengine.com/community/community-content-tools-and-tutorials/1257-3ds-max-object-placement-scripts
https://forums.unrealengine.com/community/community-content-tools-and-tutorials/11358-introducing-3ds-max-to-ue4-fbx-and-t3d-exporter-maxscript
"""

# exports each selected object into its own file
import bpy
import os
import math

# OPTIONS =====================================================================
# unreal path to imported assets
packagename = "/Game/Meshes/"
# TODO OPTIONS
# do FBX export
# FBX output path
# do FBX export from origin
# do T3D export
# T3D output path
# T3D scale x100



# export to blend file location
basedir = os.path.dirname(bpy.data.filepath)
if not basedir:
    raise Exception("Blend file is not saved")


scene = bpy.context.scene
obj_active = scene.objects.active
selection = bpy.context.selected_objects
bpy.ops.object.select_all(action='DESELECT')

unique_objects=[]
t3dstring="\n"
t3dstring += ("Begin Map\n")
t3dstring += ("   Begin Level\n")
for obj in selection:
    obj.select = True
    scene.objects.active = obj

    obj_name = bpy.path.clean_name(obj.name)
    data_name = bpy.path.clean_name(obj.data.name)
    fn = os.path.join(basedir, data_name)
    
    # find unique object data and export only those FBXs
    if data_name not in unique_objects:
        unique_objects.append(data_name)
        # 1 store matrix        
        #obj_matrix = obj.matrix_world
        loc, rot, scale = obj.matrix_world.decompose()
        # 2 reset matrix        
        #obj.matrix_world.identity()
        bpy.ops.object.location_clear(clear_delta=False)
        bpy.ops.object.rotation_clear(clear_delta=False)
        bpy.ops.object.scale_clear(clear_delta=False)
        # 3 export
        bpy.ops.export_scene.fbx(filepath=fn + ".fbx", use_selection=True)
        # 4 restore matrix        
        #obj.matrix_world = obj_matrix
        #bpy.context.scene.update()
        bpy.context.object.location = loc
        bpy.context.object.rotation_euler = rot.to_euler()
        bpy.context.object.scale = scale
    
    # generate T3D for each object instance, reference unique FBX names
    t3dstring += ("      Begin Actor Class=StaticMeshActor Name=" + obj_name + " Archetype=StaticMeshActor'/Script/Engine.Default__StaticMeshActor'\n")
    t3dstring += ("         Begin Object Class=StaticMeshComponent Name=StaticMeshComponent0 Archetype=StaticMeshComponent'Default__StaticMeshActor:StaticMeshComponent0'\n")
    t3dstring += ("         End Object\n")
    t3dstring += ("         Begin Object Name=StaticMeshComponent0\n")
    t3dstring += ("            StaticMesh=StaticMesh'" + packagename + data_name + "." + data_name + "'\n")
    t3dstring += ("            RelativeLocation=(")
    t3dstring += ("X=" + str(obj.location[0]*100.0) + ",")
    t3dstring += ("Y=" + str(obj.location[1]*-100.0) + ",")
    t3dstring += ("Z=" + str(obj.location[2]*100.0) + ")\n")
    t3dstring += ("            RelativeRotation=(")
    t3dstring += ("Roll="  + str(math.degrees( obj.rotation_euler[0])) + ",")    
    t3dstring += ("Pitch=" + str(math.degrees( obj.rotation_euler[1])) + ",")
    t3dstring += ("Yaw="   + str(math.degrees(-obj.rotation_euler[2])) + ")\n")
    t3dstring += ("            RelativeScale3D=(")
    t3dstring += ("X=" + str(obj.scale[0]) + ",")
    t3dstring += ("Y=" + str(obj.scale[1]) + ",")
    t3dstring += ("Z=" + str(obj.scale[2]) + ")\n")
    t3dstring += ("         End Object\n")
    t3dstring += ("         StaticMeshComponent=StaticMeshComponent0\n")
    t3dstring += ("         RootComponent=StaticMeshComponent0\n")
    t3dstring += ("         ActorLabel=\"" + obj_name + "\"\n")
    t3dstring += ("      End Actor\n")
    obj.select = False
t3dstring += ("   End Level\n")
t3dstring += ("Begin Surface\n")
t3dstring += ("End Surface\n")
t3dstring += ("End Map\n")

print(t3dstring)
unique_objects.clear()

# restore selection
for obj in selection:
    obj.select = True
scene.objects.active = obj_active