Source code for snnib.blender.utils.geo_nodes_utils
"""utilities to manipulate blenders geometry nodes
Exceptions
Classes
Functions
- `add_todo_node()`
- `copy_geonodes()`
- `clear_node_group()`
- `create_node_group()`
- `delete_geonode_groups()`
- `exists_node_group()`
- `get_node_by_label()`
- `set_node_curve()`
Other Objects
"""
#%%imports
import bpy
import logging
from typing import List, Tuple, Union
logger = logging.getLogger(__name__)
logging.basicConfig(level=logging.INFO)
#%%definitions
[docs]
def add_todo_node(
node_group:bpy.types.GeometryNodeTree,
location:Tuple[float,float]=(0.0,0.0),
) -> bpy.types.Node:
"""adds a frame denoting a TODO to the node tree
Parameters
- `node_group`
- `bpy.types.GeometryNodeTree`
- geo nodes node tree to attach the node to
- `location`
- `Tuple[float,float]`, optional
- location as `(x,y)` of the node
- the default is `(0.0,0.0)`
Raises
Returns
- `n_todo`
- `bpy.types.Node`
- created node
Dependencies
- `bpy`
- `logging`
- `typing`
"""
n_todo = node_group.nodes.new(type="NodeFrame")
n_todo.label = "TODO"
n_todo.use_custom_color = True
n_todo.label_size = 45
n_todo.color = (1.0,0.4,0.0)
n_todo.location = location
return n_todo
[docs]
def copy_geonodes(
src:bpy.types.Object, targ:bpy.types.Object,
) -> bpy.types.NodesModifier:
"""sets the geo nodes modifier of `targ` to the same as `src`
- only applies to first found geo nodes modifier
- no action if no geo nodes modifier found
Parameters
- `src`
- `bpy.types.Object`
- source to copy geo nodes modifier from
- `targ`
- `bpy.types.Object`
- target to copy geo nodes modifier to
Raises
Returns
- `targ_gn_mod`
- `bpy.types.NodesModifier`
- created geo nodes modifier
Dependencies
- `bpy`
- `logging`
- `typing`
"""
#get source modifier
src_gn_mod = None
for mod in src.modifiers:
if mod.type == "NODES":
src_gn_mod = mod
break
if src_gn_mod is None:
logger.warning("no geonodes found... ignoring...")
return {'FINISHED'}
# Add a new Geometry Nodes modifier to the target
targ_gn_mod = targ.modifiers.new(name=src_gn_mod.name, type='NODES')
# Copy the node group from the source modifier
targ_gn_mod.node_group = src_gn_mod.node_group
return targ_gn_mod
[docs]
def clear_node_group(
group_name:str
):
"""clears the node group of `group_name`
- used to avoid cluttering in blender file when developing new node group
- allow to stay in node group and see changes when rerunning scripts
Parameters
- `group_name`
- `str`
- name of the targeted geo nodes group
Raises
Returns
Dependencies
- `bpy`
- `logging`
- `typing`
"""
for ng in bpy.data.node_groups:
if group_name==ng.name:
ng.nodes.clear()
ng.links.clear()
ng.interface.clear()
return {'FINISHED'}
[docs]
def create_node_group(
group_name:str, dev:bool
) -> bpy.types.GeometryNodeTree:
"""returns existing node group if `dev`, otherwise always creates new one
- helper creating node groups based on specifications
- overrides existing nodes when `dev==True` (creates new group if nonexistent)
- creates new group without overriding if `dev!=True`
Parameters
- `group_name`
- `str`
- name of the targeted geo nodes group
- `dev`
- `bool`, optional
- flag denoting if script is ran in development mode
Raises
Returns
- `node_group`
- `bpy.types.GeometryNodeTree`
- created geo nodes node group
Dependencies
- `bpy`
- `logging`
- `typing`
"""
#node creation
if dev:
clear_node_group(group_name)
if not exists_node_group(group_name):
#new node group if it does not exist yet
node_group = bpy.data.node_groups.new(name=group_name, type='GeometryNodeTree')
else:
node_group = bpy.data.node_groups[group_name]
else:
#new node group regardless (will enumerate if existent)
node_group = bpy.data.node_groups.new(name=group_name, type='GeometryNodeTree')
return node_group
[docs]
def delete_geonode_groups(
group_name:str
):
"""deletes all geometry node node groups with name `group_name`
- used before generating new groups to avoid cluttering blender
Parameters
- `group_name`
- `str`
- name of the targeted geo nodes group
Raises
Returns
Dependencies
- `bpy`
- `logging`
- `typing`
"""
#get all matching goroups
to_delete = [ng for ng in bpy.data.node_groups if ng.name == group_name and ng.bl_idname == "GeometryNodeTree"]
#remove found groups
for ng in to_delete:
bpy.data.node_groups.remove(ng)
return {'FINISHED'}
[docs]
def exists_node_group(
group_name:str
):
"""returns flag whether node group of `group_name` already exists
- used to avoid cluttering in blender file when developing new node group
- allows creation of new group only if it is not existing already
Parameters
- `group_name`
- `str`
- name of the targeted geo nodes group
Raises
Returns
Dependencies
- `bpy`
- `logging`
- `typing`
"""
return any([group_name==ng.name for ng in bpy.data.node_groups])
[docs]
def get_node_by_label(
node_tree:bpy.types.GeometryNodeTree,
label:str,
) -> bpy.types.Node:
"""returns first node in `node_tree` that matches `label`
Parameters
- `node_tree`
- `bpy.types.GeometryNodeTree`
- geometry nodes node tree to extract node from
- `label`
- `str`
- label of the node to search for
Raises
Returns
- `node`
- `bpy.types.Node`
- extracted node
- `None` if no matching node was found
Dependencies
- `bpy`
- `logging`
- `typing`
"""
for node in node_tree.nodes:
if node.label == label:
return node
return None
[docs]
def set_node_curve(
node:bpy.types.ShaderNodeRGBCurve,
channel_index:int,
pts:List[List[float]],
handle_types:List[str]=None
):
"""overrides node curve (i.e. RGB Curves node) with new curve
Parameters
- `node`
- `bpy.types.ShaderNodeRGBCurve`
- node to update the curve of
- `channel_index`
- `int`
- index of the channel to target
- 0 > r
- 1 > g
- 2 > b
- 3 > combined
- `pts`
- `List[List[float]]`
- coordinates to place the control points at
- `handle_types`
- `List[str]`, optional
- handle types to use for each point in `pts`
- the default is `None`
- uses default settings
Raises
Returns
Dependencies
- `bpy`
- `logging`
- `typing`
"""
curve = node.mapping.curves[channel_index]
#keep endpoints only
while len(curve.points) > 2:
curve.points.remove(curve.points[1])
for (x, y) in pts:
curve.points.new(x, y)
#remove old first points
curve.points.remove(curve.points[0])
#remove old last points
# for p in curve.points: print(p.location)
curve.points.remove(curve.points[-2])
#set handle types
if handle_types is not None:
for idx, ht in enumerate(handle_types):
curve.points[idx].handle_type = ht
#apply changes
node.mapping.update()
return {'FINISHED'}
#%%registration
def register():
pass
def unregister():
pass
