Not so feature rich blender exporter (to a custom binary file format). #python #blender #model

blender_exporter.py

"""
    Exports a blender model into my binary model format.
    
    Python: 3.2
    Blender: 263
    Author: Eduárd Mándy
"""

"""
MBM FILE SRUCTURE

HEADERS

struct sHeader
{
    unsigned int numObjects;
    unsigned int numMaterials;
    unsigned int offsetObjects;
    unsigned int offsetMaterials;
};

struct sObjects
{
    unsigned int materialID;
    unsigned int numVertices;
    unsigned int numTexCoords;
    unsigned int numNormals;
    unsigned int numFaceIndices;
    unsigned int offsetVertices;
    unsigned int offsetTexCoords;
    unsigned int offsetNormals;
    unsigned int offsetFaceIndices;
};

struct sMaterials
{
    unsigned int lengthTexFileName;
    unsigned int offsetTexFileName;
};

DATA

texFileNames
vertices
texCoords
normals
faceIndices

"""

import bpy
import array

headerSize     = 16
objectsSize    = 36
materialsSize  = 8

numObjects        = len(bpy.data.meshes)
numMaterials      = numObjects
offsetObjects     = headerSize
offsetMaterials   = offsetObjects   + objectsSize   * numObjects

header         = []
objects        = []
materials      = []
texFileNames   = []
vertices       = []
texCoords      = []
normals        = []
faceIndices    = []

positionOffset = []

offsetTexFileName = []
offsetVertices    = []
offsetTexCoords   = []
offsetNormals     = []
offsetFaceIndices = []

"""
    SET POSITION OFFSET
"""
for object in bpy.data.objects:
    if object.type == "MESH":
        x = object.matrix_local[0].w
        y = object.matrix_local[1].w
        z = object.matrix_local[2].w
        positionOffset.append([x, y, z])

"""
    SET DATA
"""
i = 0

for mesh in bpy.data.meshes:
    
    # set texture file names
    tempString = mesh.materials[0].active_texture.image.name
    tempList   = [ord(c) for c in tempString]
    texFileNames.extend( tempList )
    
    #set vertices
    for vertex in mesh.vertices:
        x = vertex.co.x
        y = vertex.co.y
        z = vertex.co.z
        vertices.extend( [ y+positionOffset[i][1], z+positionOffset[i][2], x+positionOffset[i][0] ] )
    
    i += 1
        
    # set texture coordinates
    for data in mesh.uv_layers.active.data:
        texCoords.extend( data.uv ) 

    # set normals
    for polygon in mesh.polygons:
        normals.extend( polygon.normal )

    # set face indices
    for polygon in mesh.polygons:
        faceIndices.extend( polygon.vertices )  

"""
    SET OFFSETS
"""

offset = headerSize + objectsSize * numObjects + materialsSize * numMaterials

# offsetTexFileName
for mesh in bpy.data.meshes:
    offsetTexFileName.append(offset)
    offset += len( mesh.materials[0].active_texture.image.name )

# offsetVertices
for mesh in bpy.data.meshes:
    offsetVertices.append(offset)
    offset += len(mesh.vertices) * 12

# offsetTexCoords
for mesh in bpy.data.meshes:
    offsetTexCoords.append(offset)
    offset += len(mesh.uv_layers.active.data) * 8

# offsetNormals
for mesh in bpy.data.meshes:
    offsetNormals.append(offset)
    offset += len(mesh.polygons) * 12

# offsetFaceIndices
for mesh in bpy.data.meshes:
    offsetFaceIndices.append(offset)
    offset += len(mesh.polygons) * 12

"""
    SET HEADER
"""
header.append( numObjects )
header.append( numMaterials )
header.append( offsetObjects )
header.append( offsetMaterials )

"""
    SET OBJECTS
"""
mesh = bpy.data.meshes

for i in range(numObjects):
    objects.append( i )                                      # materialID
    objects.append( len( mesh[i].vertices ) )                # numVertices
    objects.append( len( mesh[i].uv_layers.active.data ) )   # numTexCoords
    objects.append( len( mesh[i].polygons ) )                # numNormals
    objects.append( len( mesh[i].polygons ) * 3 )            # numFaces
    objects.append( offsetVertices[i] )
    objects.append( offsetTexCoords[i] )
    objects.append( offsetNormals[i] )
    objects.append( offsetFaceIndices[i] )

"""
    SET MATERIALS DATA
"""
for i in range(numObjects):
    materials.append( len( mesh[i].materials[0].active_texture.image.name ) )
    materials.append( offsetTexFileName[i] )

"""
    WRITE TO BINARY FILE
"""
f = open("2planes2.mbm", "wb")

headerArray       = array.array('i', header)
objectsArray      = array.array('i', objects)
materialsArray    = array.array('i', materials)
texFileNamesArray = array.array('b', texFileNames)
verticesArray     = array.array('f', vertices)
texCoordArray     = array.array('f', texCoords)
normalsArray      = array.array('f', normals)
facesIndArray     = array.array('i', faceIndices)


headerArray.tofile(f)
objectsArray.tofile(f)
materialsArray.tofile(f)
texFileNamesArray.tofile(f)
verticesArray.tofile(f)
texCoordArray.tofile(f)
normalsArray.tofile(f)
facesIndArray.tofile(f)

f.close()

print("MBM Export done")