Hair editing techniques for animation

A method for configuring hair for animation, the method comprising performing, by a computer system:

• obtaining a first representation of a set of hairs on a surface, wherein the surface comprises a mesh with vertices;
• generating a second representation of a subset of the set of hairs;
• at a vertex of the surface, generating an interpolated hair by minimizing a shape difference between a first hair of the subset of the hairs and the interpolated hair;
• receiving an edit to modify a shape of the first hair to generate a modified hair;
• at the vertex of the surface, generating a modified interpolated hair by minimizing the shape difference between the modified hair and the modified interpolated hair;
• projecting the interpolated hair onto a root of a second hair of the set of hairs on the surface, thereby generating a projected interpolated hair;
• projecting the modified interpolated hair onto the root of the second hair of the set of hairs on the surface, thereby generating a projected modified interpolated hair;
• generating one or more rotation parameters indicating a rotation between the projected interpolated hair and the projected modified interpolated hair;
• computing a scaling factor indicating a scale difference between the projected interpolated hair and the projected modified interpolated hair;
• and
• applying the one or more rotation parameters and the scaling factor to the second hair of the set of hairs on the surface to propagate the edit to the second hair of the set of hairs on the surface.