convert 3d model to header using assimp

models.py

#####
##### By Christopher Pugh
##### Copyright 2015 Virtuoso Engine, LLC
##### Public domain or equivalent license
#####
##### Basic asset to header script
##### Pulls vertices, normals, single texture coord channel
##### Triangulates meshes, pulls multiple meshes, puts everything in arrays in a namespace
##### first argument is input mesh file
##### Second optional argument is namespace name
##### Powered by Assimp Python API
##### Uses {NAMESPACE}_DEFINITIONS guard like an STB library to switch the header between declarations and definitions only

#todo variable naming breaks if there's more than one mesh
#todo use argparse like env tool to add flags like capping bone counts, etc

from pyassimp import *
import sys

def processNodes(node, nodes):
	print (node.name)

	nodes[node.name] = [node, False]

	for n in node.children:
		processNodes(n, nodes)

aiPrimitiveType_POINT = 1
aiPrimitiveType_LINE = 2
aiPrimitiveType_TRIANGLE = 4
aiPrimitiveType_POLYGON = 8

primNames = {}
primNames[aiPrimitiveType_POLYGON] = "polygon"
primNames[aiPrimitiveType_LINE] = "line"
primNames[aiPrimitiveType_TRIANGLE] = "triangle"
primNames[aiPrimitiveType_POINT] = "point"

print ('Number of arguments:', len(sys.argv), 'arguments.')
print ('Argument List:', str(sys.argv), "\n")

if len(sys.argv) < 2:
	print ("Improper usage : Too few arguments")
	exit()

print ("Loading asset " + sys.argv[1])


if len(sys.argv) >= 3 :
    namespace = sys.argv[2]
else:
    print "Using default file name and namespace \'mesh\'"
    namespace = "mesh"

flags = postprocess.aiProcess_ImproveCacheLocality
flags |= postprocess.aiProcess_JoinIdenticalVertices
flags |=  postprocess.aiProcess_Triangulate
flags |= postprocess.aiProcess_RemoveRedundantMaterials
flags |= postprocess.aiProcess_SortByPType
flags |= postprocess.aiProcess_OptimizeMeshes
flags |= postprocess.aiProcess_OptimizeGraph
#flags = postprocess.aiProcess_PreTransformVertices
flags |= postprocess.aiProcess_LimitBoneWeights

scene = load(sys.argv[1], processing=flags)

print ("Number of meshes " + str(len(scene.meshes)))
print ("Number of animations " + str(len(scene.animations)))
print ("Number of lights " + str(len(scene.lights)))
print ("Number of textures " + str(len(scene.textures)))
print ("Number of materials " + str(len(scene.materials)))
print ("Number of cameras " + str(len(scene.cameras)))

print ("\nEnumerating Meshes")

mergeIndices = True

#print animations
nodes = {}
processNodes(scene.rootnode, nodes)


namespaceMod = namespace.upper()
namespaceMod.replace(" ", "_")
headerGuardDefine = namespaceMod + "_H_INCLUDED"

f = open(namespace + '.h', 'w')

f.write ("\nnamespace " + namespace + "\n{\n")

namespaceDefinitions = namespaceMod + '_DEFINITIONS'

f.write ('\n#ifndef ' + namespaceDefinitions + '\n\n')
f.write ("\n\nextern const unsigned int " + namespaceMod + "_NUM_MESHES;\n\n")
f.write("#ifndef _" + headerGuardDefine + "\n#define _" + headerGuardDefine + "\n")
for i,m in enumerate(scene.meshes) :
    f.write('extern int indices' + str(i) + '[];\n')
    f.write('extern float vertices' + str(i) + '[];\n')
    f.write('extern float normals' + str(i) + '[];\n')
    f.write('extern float texcoords' + str(i) + '[];\n\n')

arrtype = ["int", "float", "float", "float"];
arrvar = ["indices", "vertices", "texcoords", "normals"];

namespacevar = namespace.replace(" ", "_")

for x in range(0, len(arrtype)) :
    f.write ('extern ' + arrtype[x] + "* " + namespacevar + "_" + arrvar[x] + "[" + str(len(scene.meshes)) + '];\n')

f.write("\n#endif // " + headerGuardDefine)
f.write('\n\n#else\n\n')

f.write ("\n\nconst unsigned int " + namespaceMod + "_NUM_MESHES = " + str(len(scene.meshes)) + ';\n\n')

idxOffset = 0

for i,m in enumerate(scene.meshes) :
	print ("\nmesh %d" % (i))
	print ("\tfaces %d " % len(m.faces))
	print ("\tvertices %d "%len(m.vertices))
	print ("\ttexcoord channels %d "%len(m.texturecoords))
	print ("Primitive type : " + primNames[m.primitivetypes])

	if m.primitivetypes != aiPrimitiveType_TRIANGLE:
		print ("Error: Non-triangle meshes not supported")
		exit()

	#write indices
	f.write('int indices' + str(i) + '[] = {')

	for fac in m.faces:
		for fc in fac:
			fc2 = fc
			if mergeIndices:
				fc2 = fc + idxOffset

			f.write("%d, "%fc2)
		#f.write(%d)
	f.write('};')

	#write vertices
	f.write("\n\nfloat vertices" + str(i) + "[] = {")

	for vert in m.vertices:
		for c in vert:
			f.write("%f, "%c )

	f.write("};")

	#write tex coords
	f.write("\n\nfloat texcoords" + str(i) + "[] ={")

	for uv in m.texturecoords[0]:
		f.write(str(uv[0]) + ", " + str(uv[1]) + ", ")
	f.write("};")


	#write normals
	f.write("\n\nfloat normals" + str(i) + "[] ={")

	for n in m.normals:
		for z in n :
			f.write(str(z) + ", ")
	f.write("};\n\n\n")

	idxOffset += len(m.vertices)

#arrtype = ["int", "float", "float", "float"];
#arrvar = ["indices", "vertices", "texcoords", "normals"];

#namespacevar = namespace.replace(" ", "_")

for x in range(0, len(arrtype)) :
    f.write (arrtype[x] + "* " + namespacevar + "_" + arrvar[x] + "[" + str(len(scene.meshes)) + '] = {')

    for i,m in enumerate(scene.meshes) :
        f.write(arrvar[x] + str(i) + ',')

    f.write ('};\n\n')
f.write("\n\n#endif //" + namespaceDefinitions)
f.write ("\n} // namespace " + namespace)
release (scene)