import numpy as np

class MaterialCache:

''' The Material Cache exports blender objects to numpy arrays of data

(Just colors for now)

'''

def __init__(self):

self.materials = [] # a list of materials index = id

def add(self, blender_material):

if blender_material not in self.materials:

self.materials.append(blender_material)

def commit(self):

''' save the material data to a temp numpy array '''

if len(self.materials) == 0:

# fix if there is no materials

self.color = np.array([[1.0, 0.0, 1.0, 1.0]], dtype=np.float32)

self.emission_color = np.array([[1.0, 0.0, 1.0, 1.0]], dtype=np.float32)

else:

self.color = np.array([get_color(mat) for mat in self.materials], dtype=np.float32)

self.emission_color = np.array([get_emission_color(mat) for mat in self.materials], dtype=np.float32)

def get_index(self, blender_material):

self.add(blender_material)

return self.materials.index(blender_material)

def get_color(material):

if material is None:

return [0.0, 0.0, 0.0, 0.0]

else:

return list(material.diffuse_color)

def get_emission_color(material):

col = [0.0, 0.0, 0.0, 0.0]

if material is not None:

# only return the emission color for node graphs with emission nodes only.

if material.node_tree is not None:

nodes = material.node_tree.nodes

for node in nodes:

if node.bl_idname == 'ShaderNodeOutputMaterial':

from_node = node.inputs['Surface'].links[0].from_node

if from_node.bl_idname == 'ShaderNodeEmission':

col = np.array(list(from_node.inputs['Color'].default_value), dtype=np.float32) * from_node.inputs['Strength'].default_value

return col