Marching Squares on Surface¶

https://user-images.githubusercontent.com/14288520/209465511-338c7076-3c26-4106-bdca-36bc5a8db283.png

Dependencies¶

This node requires SkImage library to work.

Functionality¶

This node uses Marching Squares algorithm to find iso-lines of a scalar field on an arbitrary surface, i.e. lines for which the value of scalar field equals to the given value at each point. The lines are generated as mesh - vertices and edges. You can use one of interpoolation nodes to build Curve objects from them.

https://user-images.githubusercontent.com/14288520/209466874-7456e36b-9b90-44ae-994a-f8216ac87345.png

Inputs¶

This node has the following inputs:

Field. Scalar field to generate iso-lines for. This input is mandatory.

https://user-images.githubusercontent.com/14288520/209467485-6a6d7c4e-db29-4c5c-879d-50234ba3d025.png

Surface. The surface to draw iso-lines on. This input is mandatory.

https://user-images.githubusercontent.com/14288520/209468044-c5e6ef77-e135-4a12-829c-ed20111056a6.png

Value. The value of scalar field, for which to generate iso-lines. The default value is 1.0.

https://user-images.githubusercontent.com/14288520/209468136-e27b8450-aecb-4905-9cff-c40868f8c8d6.png

SamplesU, SamplesV. Number of samples along U and V parameter of the surface, correspondingly. This defines the resolution of curves: the bigger isvalue, the more vertices will the node generate, and the more precise the curves will be. But higher resolutioln requires more computation time. The default value is 50 for both inputs.

https://user-images.githubusercontent.com/14288520/209472279-1d451e4d-ae49-4286-bb8d-ef28462af018.png

Parameters¶

This node has the following parameters:

Join by surface. If checked, then mesh objects generated for each separate contour on one surface will be merged into one mesh object. Otherwise, separate mesh object will be generated for each contour. Checked by default.
Connect boundary. If checked, the node will connect pieces of the same curve, that was split because it was cut by the boundary of the surface. Otherwise, several separate pieces will be generated in such case. Note that this node can not currently detect if the surface is closed to glue parts of contours at different sides of the surface. Checked by default.

https://user-images.githubusercontent.com/14288520/209476502-77ebe3aa-bba9-4742-a9eb-6b1c70699b32.png

Outputs¶

This node has the following outputs:

Vertices. Generated iso-curves vertices in 3D space.
Edges. Edges connecting iso-curve vertices.
UVVertices. Points in surface’s U/V space, corresponding to generated iso-curve vertices.