Houdini 20.5 Nodes Copernicus nodes

Eikonal Copernicus node

Computes distances by solving the Eikonal Equation.

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This esoteric node solves the Eikonal Equation .

The idea is to build a Mono layer where the speed at which the values are changing matches a reference speed. If the reference speed is 1, this results in a distance field.

A one-sided solution is found where pixels can decrease in value, but never increase. Thus black pixels will act as sources and white pixels will be replaced by the distance to the closest black pixel. The seed field controls how easy it is to traverse the pixel - a value of 0 stops propagation so can be used as boundaries.

Parameters

Speed

Global rate of change.

Iterations

A single iteration is sufficient to converge if there is a uniform speed field. But if the speed varies in complicated fashions, it may require more passes for the distances to fully propagate.

Tile Size

The layer is broken up into blocks of this size. This helps balance the serial and parallel components of the algorithm. If it has converged, this should have no effect on the behaviour. The default values should be sufficient.

Inputs

initial_dist

A Mono layer of the original distances. These can only decrease in value, so usually “sources” are made black and the rest is filled to large values, such as 60000.

speed

A Mono layer to control the speed on a per-pixel manner. Zero areas will act like boundaries and can be used to form simple mazes. Note additional iterations may then be needed.

Outputs

sdf

A Mono layer that becomes a distance field, subject to the provided speed values. Note this is not a signed distance field - another pass is required to decide if voxels are inside or outside.

See also

Copernicus nodes