## Make Parametric Object (vuo.scene.make.parametric) Creates a scene object in a shape defined by parametric math expressions.

This node creates a mesh whose vertex positions and texture mapping are defined by a set of math expressions. The expressions can use the variables U and V. This node calculates each expression for evenly spaced values of U and V. Each calculation becomes a vertex in the resulting mesh.

• `Transform` — Changes the object’s translation, rotation, or scale, in Vuo Coordinates.
• `Material` — A shader, image, or color to apply to the object. If no material is provided, this node uses a default shader that stretches a gradient-colored checkerboard across the object.
• `Time` — The time at which to calculate the expressions. (This only affects the output if the `Time` variable is used in the expressions.)
• `X Expression`, `Y Expression`, `Z Expression` — The math expressions for the (X,Y,Z) position of each vertex. Typically, the values of `X Expression` should increase as U increases, and the values of `Y Expression` should increase as V increases. (Otherwise, the triangles that make up the mesh may be facing backwards, which means they won’t be drawn.)
• `Rows`, `Columns` — Each of the above expressions is calculated for `Rows` number of values of V and `Columns` number of values of U. The total number of vertices in the mesh is `Rows * Columns`.
• `U Closed`, `V Closed` — If true, then the mesh surface will wrap around from the vertices calculated for U=1 or V=1 to the vertices calculated for U=0 or V=0. If false, then either the mesh surface won’t wrap around or, if the math expressions do cause it to wrap around, any 3D scene object created from the mesh may have a visible seam.

The math expressions can use:

• Numbers
• Operators such as + and -
• Functions such as sin(U) and log(U)
• Constants such as PI
• Variables U and V — evenly spaced values from the minimum to the maximum of `U Range` and `V Range`
• Variables I and J — the integer index of the point, ranging from 1 to `Columns` and 1 to `Rows`, respectively

For a complete list of the operators and functions available, see the Calculate node’s description.

For help understanding the math used by this node, see Introduction to parametric equations and Introduction to parametrizing a surface with two parameters.

Keywords: draw, graphics, mesh, model, opengl, points, scenegraph, segments, shader, texture, vertices

### Example composition:

• Spin Shell: Animates a 3D seashell-shaped object.

Back to vuo.scene node set documentation.