Attributes
+An important concept in Geometry Nodes is attributes. Many trees transfer attributes between geometry, using a combination of Capture Attribute and Transfer Attribute.
+Unfortunately, it takes quite a bit of code to use this common pattern.
+@tree("Skin")
+def skin():
+ # Create a cube
+ c = cube()
+ # Capture the position
+ cube_position_attribute = c.capture_attribute(
+ data_type=CaptureAttribute.DataType.FLOAT_VECTOR,
+ value=position()
+ )
+ # Create a sphere
+ sphere = uv_sphere()
+ # Transfer the position to the sphere
+ transferred_position = cube_position_attribute.geometry.transfer_attribute(
+ data_type=TransferAttribute.DataType.FLOAT_VECTOR,
+ attribute=cube_position_attribute.attribute
+ )
+ # Make the sphere conform to the shape of the cube
+ return sphere.set_position(position=transferred_position)
+Thankfully, a convenient capture(...) method is available on Geometry, which simplifies this function quite a bit.
@tree("Skin")
+def skin():
+ # Create a cube
+ c = cube()
+ # Capture the position
+ cube_position = c.capture(position())
+ # Create a sphere
+ sphere = uv_sphere()
+ # Make the sphere conform to the shape of the cube
+ return sphere.set_position(position=cube_position())
+How it Works
+Internally, capture(...) works just like the more manual approach.
-
+
- Capture the attribute from the source +
In the example above, we capture the position() from the cube.
+The data type is automatically inferred from the input. If you want to customize other options, simply pass them as keyword arguments to capture(...).
cube_position = c.capture(position())
+cube_position = c.capture(position(), domain=CaptureAttribute.Domain.FACE) # Optionally pass other arguments available on `capture_attribute`.
+-
+
- Transfer the attribute to the target +
capture(...) returns another function that calls transfer_attribute with the correct arguments passed automatically.
+Call this returned function (which we store in the variable cube_position) to transfer the attribute.
+In this example we also set the transferred cube position back onto the sphere.
sphere.set_position(position=cube_position())
+sphere.set_position(position=cube_position(mapping=TransferAttribute.Mapping.NEAREST)) # Optionally pass other arguments available on `transfer_attribute`.
+