Houdini 20.5 Nodes Copernicus nodes

Eikonal Copernicus node

Computes distances by solving the Eikonal equation.

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This node solves the Eikonal equation . The idea is to build a mono layer where the speed at which the values change 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 (but never increase) in value. This means black pixels act as sources and white pixels are replaced by the distance to the closest black pixel. The speed field controls how easy it is to traverse the pixel, where a value of 0 stops propagation and can be used for boundaries.

Parameters

Speed

The global rate of change.

Iterations

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

Tile Size

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

Inputs

initial_dist

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

speed

A layer to control the speed on a per-pixel manner. Zero areas act like boundaries and can be used to form simple mazes.

Note

Additional iterations may be needed.

Outputs

sdf

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

See also

Copernicus nodes