Evaluate Surface

https://github.com/nortikin/sverchok/assets/14288520/27b50740-2618-43a9-895f-5959999b3112

Functionality

This node calculates points on the Surface corresponding to provided values of U and V surface parameters. The values of U and V can be either provided explicitly, or generated by the node to generate cartesian (rectangular) grid.

https://github.com/nortikin/sverchok/assets/14288520/d46ddda8-0071-4e4e-84e4-147a44d29f59

Inputs

This node has the following inputs:

  • Surface. The surface to evaluate. This input is mandatory.

  • U, V. Values of U and V surface parameter. These inputs are available only when the Evaluate parameter is set to Explicit, and Input mode parameter is set to Separate. The default value is 0.5.

  • Vertices. Points at which the surface should be evaluated. Only two of three coordinates will be used; the coordinates used are defined by Orientation parameter. This input is available and mandatory if the Evaluation mode parameter is set to Explicit, and Input mode is set to Vertices.

    https://github.com/nortikin/sverchok/assets/14288520/e8e53044-ae00-48d5-9f61-654f2fccddfb

  • SamplesU, SamplesV. Number of samples along U and V direction, used to generate cartesian grid. These inputs are available only when the Evaluate parameter is set to Grid. The default value is 25.

Parameters

This node has the following parameters:

  • Evaluate. This determines how the values of surface’s U and V parameters are defined. The available options are:

    • Explicit. U and V parameters are to be provided in inputs of this node. Depending on Input mode parameter, either U and V inputs, or Vertices input will be used.

    • Grid. The node will generate evenly-spaced cartesian grid with number of samples along U and V direction defined by SamplesU and SamplesV inputs, correspondingly.

    The default mode is Grid.

  • Input mode. This parameter is available only when Evaluate parameter is set to Explicit. The available options are:

    • Separate. The values of U and V surface parameters will be provided in U and V inputs, correspondingly.

    • Vertices. The values of U and V surface parameters will be provided in Vertices input; only two of three coordinates of the input vertices will be used.

    The default mode is Separate.

  • Input orientation. This parameter is available only when Evaluate parameter is set to Explicit, and Input mode parameter is set to Vertices. This defines which coordinates of vertices provided in the Vertices input will be used. The available options are XY, YZ and XZ. For example, if this is set to XY, then the X coordinate of vertices will be used as surface U parameter, and Y coordinate will be used as V parameter. The default value is XY.

  • Clamp. This parameter is available only when Evaluate parameter is set to Explicit. This defines how the node will process the values of surface U and V parameters which are out of the surface’s domain. The available options are:

    • As is. Do not do anything special, just pass the parameters to the surface calculation algorithm as they are. The behaviour of the surface when the values of parameters provided are out of domain depends on specific surface: some will just calculate points by the same formula, others will give an error.

    • Clamp. Restrict the parameter values to the surface domain: replace values that are greater than the higher bound with higher bound value, replace values that are smaller than the lower bound with the lower bound value. For example, if the surface domain along U direction is [0 .. 1], and the value of U parameter is 1.05, calculate the point of the surface at U = 1.0.

    • Wrap. Wrap the parameter values to be within the surface domain, i.e. take the values modulo domain. For example, if the surface domain along U direction is [0 .. 1], and the value of U parameter is 1.05, evaluate the surface at U = 0.05.

    The default mode is As is.

Outputs

This node has the following outputs:

  • Vertices. The calculated points on the surface.

  • Edges. The edges of cartesian grid on the surface. This output is only available when the Evaluate parameter is set to Grid.

  • Faces. The faces of cartesian grid on the surface. This output is only available when the Evaluate parameter is set to Grid.

Examples of usage

The node used in Grid node to generate rectangular grid on the plane:

https://user-images.githubusercontent.com/284644/78699409-4b25c380-791d-11ea-8671-2b304e108ed1.png

An example of Explicit mode usage:

https://user-images.githubusercontent.com/284644/79249080-2dfd7180-7e96-11ea-810a-4a188536adc0.png