Initial public release

nodes/common/normal_map.py

@@ -0,0 +1,82 @@
+"""Share persistent face attributes between depth symmetry and image materials.
+
+Rotation stores pre-inversion Euler angles, face kind is 1/2/3 for front/back/wall,
+and axis is 1 for the final +X orientation. Missing attributes mean identity.
+These FACE attributes stay on the output mesh for the material consumer.
+"""
+from mathutils import Matrix
+
+from anyimage.common.object import blender_frame_rotation
+
+ROTATION_ATTRIBUTE = 'o_depth_rotation'
+FACE_ATTRIBUTE = 'o_depth_face'
+AXIS_ATTRIBUTE = 'o_depth_axis'
+
+
+def transform_object_normal_color(group, color, strength):
+    """Rotate encoded object normals, reflect backs and disable wall normal maps."""
+    nodes, links = group.nodes, group.links
+
+    def attribute(name):
+        node = nodes.new('ShaderNodeAttribute')
+        node.attribute_type = 'GEOMETRY'
+        node.attribute_name = name
+        return node
+
+    def math(operation, value, constant):
+        node = nodes.new('ShaderNodeMath')
+        node.operation = operation
+        links.new(value, node.inputs[0])
+        node.inputs[1].default_value = constant
+        return node.outputs[0]
+
+    rotation = attribute(ROTATION_ATTRIBUTE)
+    face = attribute(FACE_ATTRIBUTE)
+    axis = attribute(AXIS_ATTRIBUTE)
+    decode = nodes.new('ShaderNodeVectorMath')
+    decode.operation = 'MULTIPLY_ADD'
+    decode.inputs[1].default_value = (2., 2., 2.)
+    decode.inputs[2].default_value = (-1., -1., -1.)
+    links.new(color, decode.inputs[0])
+    base = nodes.new('ShaderNodeVectorRotate')
+    base.rotation_type = 'EULER_XYZ'
+    base.inputs['Rotation'].default_value = Matrix(blender_frame_rotation()).to_euler()
+    links.new(decode.outputs[0], base.inputs['Vector'])
+    rotate = nodes.new('ShaderNodeVectorRotate')
+    rotate.rotation_type = 'EULER_XYZ'
+    rotate.invert = True
+    links.new(base.outputs[0], rotate.inputs['Vector'])
+    links.new(rotation.outputs['Vector'], rotate.inputs['Rotation'])
+    separate = nodes.new('ShaderNodeSeparateXYZ')
+    links.new(rotate.outputs[0], separate.inputs[0])
+    back = math('COMPARE', face.outputs['Fac'], 2.)
+    # Reflect the normal's Y component on the back.
+    difference = math('MULTIPLY', separate.outputs['Y'], -2.)
+    correction = nodes.new('ShaderNodeMath')
+    correction.operation = 'MULTIPLY_ADD'
+    links.new(back, correction.inputs[0])
+    links.new(difference, correction.inputs[1])
+    links.new(separate.outputs['Y'], correction.inputs[2])
+    combine = nodes.new('ShaderNodeCombineXYZ')
+    links.new(separate.outputs['X'], combine.inputs['X'])
+    links.new(correction.outputs[0], combine.inputs['Y'])
+    links.new(separate.outputs['Z'], combine.inputs['Z'])
+    axis_rotation = nodes.new('ShaderNodeVectorMath')
+    axis_rotation.operation = 'SCALE'
+    axis_rotation.inputs[0].default_value = Matrix.Rotation(1.5707963267948966, 4, 'Z').to_euler()
+    links.new(axis.outputs['Fac'], axis_rotation.inputs['Scale'])
+    orient = nodes.new('ShaderNodeVectorRotate')
+    orient.rotation_type = 'EULER_XYZ'
+    links.new(combine.outputs[0], orient.inputs['Vector'])
+    links.new(axis_rotation.outputs[0], orient.inputs['Rotation'])
+    encode = nodes.new('ShaderNodeVectorMath')
+    encode.operation = 'MULTIPLY_ADD'
+    encode.inputs[1].default_value = (.5, .5, .5)
+    encode.inputs[2].default_value = (.5, .5, .5)
+    links.new(orient.outputs[0], encode.inputs[0])
+    mapped = math('LESS_THAN', face.outputs['Fac'], 2.5)
+    weight = nodes.new('ShaderNodeMath')
+    weight.operation = 'MULTIPLY'
+    links.new(mapped, weight.inputs[0])
+    links.new(strength, weight.inputs[1])
+    return encode.outputs[0], weight.outputs[0]