Blender 2.57 Objective-C Export Script

A few days ago, the Blender Foundation put out the first release candidate of Blender 2.5. This release unexpectedly broke compatibility with most existing 2.5 python scripts, including my Objective-C header Export Script.

Which was great timing, since I needed to use the script today. I could've just gone back to an older version of Blender, but decided instead to re-write the script to work. I just added to GitHub, the new 2.57 compatible version of the export script. This version is back to being an add-on that you can add through the User Preferences.

I've also added a few options that you can select when exporting (they're on the left side of the file selection screen, underneath the volumes and recently visited locations). You can see the new options in the following screen grab:



The first option lets you specify whether modifiers are applied before exporting the mesh. If you uncheck this, the script will strip the modifiers before exporting, otherwise, it will apply them to the mesh before exporting.

The second option will rotate the object 90° along the X axis, which converts the object from Blender's Z-up coordinate space to OpenGL's Y-up coordinate space. I've made this the default, but I could foresee situations where people would want to skip the conversion.

The final option will move the export the object using its world space coordinates rather than exporting it using object space coordinates. This option will, for example, preserve relative distance between multiple objects exported from the same file into different headers. Or, to put it another way, objects exported will normally have use their coordinates as they relate to the object's origin, regardless of where the object is in the Blender scene. If this is checked, the vertex coordinates will be exported relative to the scene's origin.

NB: There was a problem with the triangulation code in the version posted earlier. If you're having problems, pull again from GitHub.

Blender 2.5 beta 6 Objective-C Export

A kind reader updated my Objective-C export script for Blender to work with the 2.5 beta 6 version of Blender. You can find the new version on GitHub.

On a related note, if you make a change to your clone of any of my public repositories on Github, you can send me a pull request. I'm happy to take additions, bug fixes, and other updates back into the master repository.

Thanks to John Becker for updating the script!

Blender 2.5 Objective-C Export Script

Paul Horalek has taken my old Blender 2.49 script for exporting 3D objects to Objective-C header files and has ported it to the new Blender 2.5 Python API. I'd been meaning to do this for quite some time, as I've been using Blender 2.5 since the early alpha releases, but never found time. Now I don't have to.

You can find the new version of the script right here.

Thanks, Paul!

Improved Blender Export

Thanks to some help from some readers, I've got a new and improved version of the Blender Export Script for Objective-C. This new version works correctly regardless of whether there's a texture. If you've used vertex paint, it will export the vertex colors. If you have neither vertex colors or a mapped texture, then it will just export the vertices and normals. It will also update the drawing code as appropriate to the data that's been exported.

Also, new with this version, you don't need to triangulate the faces, nor do you need to apply modifiers. Those will happen automatically in the export without affecting your original model. That should make it easier to update and maintain the models you use in your iPhone apps.

You can download the new script from the link above. I'm including the script here for the curious:

Note of warning: I have not tested this script very thoroughly, so caveat emptor! Fixes and improvement suggestions welcome, as always.

#!BPY

"""
Name: 'Objective-C Header (.h)'
Blender: 244
Group: 'Export'
Tooltip: 'Exports header file for use with the OpenGL ES template for iPhone available from http://iphonedevelopment.blogspot.com/'
"""
import Blender
from Blender import *
import bpy
import bpy
import os

        
def write_obj(filepath):    
    out = file(filepath, 'w')
    sce = bpy.data.scenes.active
    ob = sce.objects.active
    mesh = Mesh.New()        
    mesh.getFromObject(ob.name)

    editmode = Window.EditMode()
    if editmode: Window.EditMode(0)
    has_quads = False
    for f in mesh.faces:
        if len(f) == 4:
            has_quads = True
            break
    
    if has_quads:
        oldmode = Mesh.Mode()
        Mesh.Mode(Mesh.SelectModes['FACE'])
        
        mesh.sel = True
        tempob = sce.objects.new(mesh)
        mesh.quadToTriangle(0) # more=0 shortest length
        oldmode = Mesh.Mode(oldmode)
        sce.objects.unlink(tempob)
        
        Mesh.Mode(oldmode)
    
    objectname = ob.getData(True)
    basename = objectname.capitalize()

    out.write('#import "OpenGLCommon.h"\n\n\n')
        
    if (mesh.faceUV):
        out.write('static const TexturedVertexData3D %sVertexData[] = {\n' % basename)
        for face in mesh.faces:
            for (vert, uvert) in zip(face.verts, face.uv):
                out.write('\t{/*v:*/{%f, %f, %f}, ' % (vert.co.x, vert.co.y, vert.co.z) )
                out.write('/*n:*/{%f, %f, %f}, ' % (vert.no.x, vert.no.y, vert.no.z))
                out.write('/*t:*/{%f, %f}' % ( uvert.x, uvert.y ) )
                out.write('},\n')
        out.write('};\n\n')
    elif (mesh.vertexColors):
        out.write('static const ColoredVertexData3D %sVertexData[] = {\n' % basename)
        for face in mesh.faces:
            for (vert, color) in zip(face.verts, face.col):
                out.write('\t{/*v:*/{%f, %f, %f}, ' % (vert.co.x, vert.co.y, vert.co.z) )
                out.write('/*n:*/{%f, %f, %f}, ' % (vert.no.x, vert.no.y, vert.no.z))
                out.write('/*c:*/{%f, %f, %f, %f}' % ( color.r / 255.0, color.g / 255.0, color.b / 255.0, color.a / 255.0) )
                out.write('},\n')
        out.write('};\n\n')
    else:
        out.write
        out.write('static const VertexData3D %sVertexData[] = {\n' % basename)
        for face in mesh.faces:
            for vert in face.verts:
                out.write('\t{/*v:*/{%f, %f, %f}, ' % (vert.co.x, vert.co.y, vert.co.z) )
                out.write('/*n:*/{%f, %f, %f} ' % (vert.no.x, vert.no.y, vert.no.z))
                out.write('},\n')
        out.write('};\n\n')
    
    if editmode: Window.EditMode(1)
    out.write('#define k%sNumberOfVertices\t%i\n' % (basename, len(mesh.faces) * 3) )

    out.write('// Drawing Code:\n')
    out.write('// glEnableClientState(GL_VERTEX_ARRAY);\n')
    if (mesh.faceUV):
        out.write('// glEnableClientState(GL_TEXTURE_COORD_ARRAY);\n')
    elif (mesh.vertexColors):
        out.write('// glEnableClientState(GL_COLOR_ARRAY);\n')
        out.write('// glEnable(GL_COLOR_MATERIAL)\n')
    out.write('// glEnableClientState(GL_NORMAL_ARRAY);\n')
    out.write('// glVertexPointer(3, GL_FLOAT, sizeof(TexturedVertexData3D), &%sVertexData[0].vertex);\n' % basename)
    out.write('// glNormalPointer(GL_FLOAT, sizeof(TexturedVertexData3D), &%sVertexData[0].normal);\n' % basename)
    if (mesh.faceUV):
        out.write('// glTexCoordPointer(2, GL_FLOAT, sizeof(TexturedVertexData3D), &%sVertexData[0].texCoord);\n' % basename)
    elif (mesh.vertexColors):
        out.write('// glColorPointer(4, GL_FLOAT, sizeof(ColoredVertexData3D), &%sVertexData[0].color);\n' % basename)
    out.write('// glDrawArrays(GL_TRIANGLES, 0, k%sNumberOfVertices);\n' % basename)
    out.write('// glDisableClientState(GL_VERTEX_ARRAY);\n')
    if (mesh.faceUV):
        out.write('// glDisableClientState(GL_TEXTURE_COORD_ARRAY);\n')
    elif (mesh.vertexColors):
        out.write('// glDisableClientState(GL_NORMAL_ARRAY);\n')
        out.write('// glDisable(GL_COLOR_MATERIAL);\n')
    out.write('// glDisableClientState(GL_NORMAL_ARRAY);\n\n\n')
    
    out.close()


filename = os.path.splitext(Blender.Get('filename'))[0]
Blender.Window.FileSelector(write_obj, "Export", '%s.h' % filename)

Thanks to Scott Lyons and Dennis Ippel for their Python and Blender API smarts. I couldn't have gotten this far without their help.