mantis/geometry_node_graphgen.py

from .utilities import (prRed, prGreen, prPurple, prWhite, prOrange,
                        wrapRed, wrapGreen, wrapPurple, wrapWhite,
                        wrapOrange,)


def gen_morph_target_nodes(mod_name, mod_ob, targets, context, use_offset=True):
    from bpy import data
    modifier = mod_ob.modifiers.new(mod_name, type='NODES')
    mod_ob.add_rest_position_attribute = True
    ng = data.node_groups.new(mod_name, "GeometryNodeTree")
    ng.interface.new_socket("Geometry", in_out="INPUT", socket_type="NodeSocketGeometry")
    ng.interface.new_socket("Geometry", in_out="OUTPUT", socket_type="NodeSocketGeometry")
    inp = ng.nodes.new("NodeGroupInput")
    out = ng.nodes.new("NodeGroupOutput")
    # TODO CLEANUP here
    if (position := ng.nodes.get("Position")) is None: position = ng.nodes.new("GeometryNodeInputPosition")
    if (index := ng.nodes.get("Index")) is None: index = ng.nodes.new("GeometryNodeInputIndex")
    rest_position = ng.nodes.new("GeometryNodeInputNamedAttribute")
    rest_position.inputs["Name"].default_value="rest_position"
    rest_position.data_type = 'FLOAT_VECTOR'
    if use_offset == False:
        rest_position = position
    add_these = []

    props_sockets={}
    object_map = {}

    for i, t in enumerate(targets):
        mt_node = t.links[0].from_node
        mt_ob = mt_node.GetxForm().bGetObject()
        if mt_ob is None: # create it
            mt_ob = data.objects.new(mt_node.evaluate_input("Name"), data.meshes.new_from_object(self_ob))
            context.collection.objects.link(mt_ob)
            prOrange(f"WARN: no object found for f{mt_node}; creating duplicate of current object ")
        mt_name = mt_ob.name
        vg = mt_node.parameters["Morph Target"]["vertex_group"]
        if vg: mt_name = mt_name+"."+vg
        try:
            ob_relative = t.links[0].from_node.inputs["Relative to"].links[0].from_node.bGetObject()
        except IndexError:
            ob_relative = None
        
        ng.interface.new_socket(mt_name, in_out = "INPUT", socket_type="NodeSocketObject")
        ng.interface.new_socket(mt_name+" Value", in_out = "INPUT", socket_type="NodeSocketFloat")
        ob_node = ng.nodes.new("GeometryNodeObjectInfo")
        sample_index = ng.nodes.new("GeometryNodeSampleIndex"); sample_index.data_type = 'FLOAT_VECTOR'
        subtract = ng.nodes.new("ShaderNodeVectorMath"); subtract.operation="SUBTRACT"
        scale1 = ng.nodes.new("ShaderNodeVectorMath"); scale1.operation="SCALE"
        

        ng.links.new(input=inp.outputs[mt_name], output=ob_node.inputs["Object"])
        ng.links.new(input=index.outputs["Index"], output=sample_index.inputs["Index"])
        ng.links.new(input=position.outputs["Position"], output=sample_index.inputs["Value"])
        ng.links.new(input=sample_index.outputs["Value"], output=subtract.inputs[0])
        ng.links.new(input=ob_node.outputs["Geometry"], output=sample_index.inputs["Geometry"])

        if ob_relative: # TODO: this should also be exposed as an input
            ob_node1 = ng.nodes.new("GeometryNodeObjectInfo"); ob_node1.inputs["Object"].default_value = ob_relative
            sample_index1 = ng.nodes.new("GeometryNodeSampleIndex"); sample_index1.data_type = 'FLOAT_VECTOR'
            ng.links.new(input=index.outputs["Index"], output=sample_index1.inputs["Index"])
            ng.links.new(input=position.outputs["Position"], output=sample_index1.inputs["Value"])
            ng.links.new(input=ob_node1.outputs["Geometry"], output=sample_index1.inputs["Geometry"])
            ng.links.new(input=sample_index1.outputs["Value"], output=subtract.inputs[1])
        else:
            # ng.links.new(input=rest_position.outputs["Attribute"], output=subtract.inputs[1])                
            ng.links.new(input=rest_position.outputs[0], output=subtract.inputs[1])

        ng.links.new(input=subtract.outputs["Vector"], output=scale1.inputs[0])

        # TODO: this should be exposed as a node tree input
        if vg:= mt_node.evaluate_input("Vertex Group"): # works
            vg_att = ng.nodes.new("GeometryNodeInputNamedAttribute"); vg_att.inputs["Name"].default_value=vg
            multiply = ng.nodes.new("ShaderNodeMath"); multiply.operation = "MULTIPLY"
            ng.links.new(input=vg_att.outputs["Attribute"], output=multiply.inputs[1])
            ng.links.new(input=inp.outputs[mt_name+" Value"], output=multiply.inputs[0])
            ng.links.new(input=multiply.outputs[0], output=scale1.inputs["Scale"])
        else:
            ng.links.new(input=inp.outputs[mt_name+" Value"], output=scale1.inputs["Scale"])
        add_these.append(scale1)
        object_map["Socket_"+str((i+1)*2)]=mt_node.GetxForm().bGetObject()
        props_sockets["Socket_"+str((i+1)*2+1)]= ("Value."+str(i).zfill(3), 1.0)
    
    set_position = ng.nodes.new("GeometryNodeSetPosition")
    bake = ng.nodes.new("GeometryNodeBake")
    ng.links.new(inp.outputs["Geometry"], output=set_position.inputs["Geometry"])
    ng.links.new(set_position.outputs["Geometry"], output=bake.inputs[0])
    ng.links.new(bake.outputs[0], output=out.inputs[0])

    if use_offset == True:
        prev_node = ng.nodes.new("FunctionNodeInputVector")
    else:
        prev_node = position
    for i, node in enumerate(add_these):
        add = ng.nodes.new("ShaderNodeVectorMath"); add.operation="ADD"
        ng.links.new(prev_node.outputs[0], output=add.inputs[0])
        ng.links.new(node.outputs[0], output=add.inputs[1])
        prev_node = add
    if use_offset == True:
        ng.links.new(add.outputs[0], output=set_position.inputs["Offset"])
    else:
        ng.links.new(add.outputs[0], output=set_position.inputs["Position"])
    
    try:
        from .utilities import SugiyamaGraph
        SugiyamaGraph(ng, 12)
    except ImportError:
        pass # this is unlikely to fail since I package the wheel but if it does it shouldn't crash out.

    for socket, ob in object_map.items():
        modifier[socket]=ob
    return modifier, props_sockets