Attribute Transfer Options

Domain Combinations

Source Domain	Result Domain	Topology	Raycast	Nearest	Nearest Interpolated	Matching Attribute (normals)
Point	Point	x		x		x
Point	Edge	x		x	x	x
Point	Face	x		x	x	x
Point	Corner	?	?	?	?	?
Edge	Point	x		x	x	x
Edge	Edge	x		x	x	x
Edge	Face	x		x	x	x
Edge	Corner	?	?	?	?	?
Face	Point	x	x	x	x	x
Face	Edge	x	x	x	x	x
Face	Face	x	x	x	x	x
Face	Corner	?	?	?	?	?
Corner	Point	x	x	x	x	x
Corner	Edge	x	x	x	x	x
Corner	Face	x	x	x	x	x

The source domain is just chosen automatically based on the source attribute which could be implicitly interpolated in many cases.

Modes

• Topology
  • Does a straight copy of arrays, error if different size
  • Doesn't have any other settings
• Raycast
  • Always "Surface Interpolated"
  • Uses another direction vector attribute on the result geometry to fire a ray at the other geometry to figure out the point to use.
  • Could possibly be interpolated or just use the closest element of the source attribute
• Nearest
  • Can possibly do sampling with bary coords, or just pick the value at the closest element
  • No interpolation
• Attribute
  • No interpolation possible
  • This can emulate the data transfer modifier's "closest normal" behavior, but much more generally.
  • This is a bit harder to visualize since it's not even really "3D" in some cases.
  • The non-interpolated "Nearest" mode with the position attribute is exactly the same thing in some cases
  • Interpolate source attribute to face domain and use that value?

Option 1

• Topology
• Raycast
• Nearest
• Nearest Interpolated
• Comparison attribute (normals)

Option 2

• Mode
  • Topology
  • Raycast
  • Attribute
  • Nearest
• Interpolated
  • Only shows when "Raycast" or "Nearest" are selected
• Direction Attribute
  • Used for raycast mode
• Comparison Attribute
  • Used for attribute mode

Option 3

• Mode
  • Topology
  • Attribute
  • Raycast (always interpolated)
  • Nearest
  • Nearest interpolated
• Direction attribute
• Comparison attribute

Option 4

• Mode
  • Topology
  • Attribute (also "position")
  • Nearest interpolated
• Direction attribute
• Comparison attribute

Option 5

• Mode
  • Topology
  • Attribute
  • Nearest face interpolated
  • Nearest edge interpolated
• Direction attribute
• Comparison attribute

Option 6

• Mode
  • Topology
  • Attribute
  • Nearest
  • Nearest point interpolated
  • Nearest face interpolated
  • Nearest edge interpolated
• Direction attribute
• Comparison attribute

Final Questions

• Does it make sense to expand "Nearest Interpolated" into a separate option for each attribute?
  • I don't think so, since you can just use the attribute convert node on the source mesh if you really need to
• Does combining "Nearest point" and "Attribute" mode make sense?
  • Technically it seems fine but might be more confusing