Houdini 12 Nodes Surface nodes

Relaxes UVs by pulling them out toward the edges of the texture area.

UVPelt operates very similar to how a tanner creates a pelt. Cuts are made to the geometry to produce a surface topologically equivalent to a disc. The boundaries of this surface are connected to a frame and stretched out.

Any closed face can be used as a frame for the pelt. A circle is used if no frame is specified. A hint polygon is used to specify which section of the geometry to pelt after performing the cuts. The boundary with an edge closest to the hint polygon is the one connected to the frame. The frame is parameterized to the range [0, 1). The boundary points are spaced around the frame at distances in the frame’s parameterization that are proportional to the edge length with the neighboring boundary point.

The effect of this operation is best visualized in the UV viewport, or with textures turned on in the 3D viewport.

XYZ

Corresponds to distance on the geometry.

UVW

Corresponds to distance in UVW (texture) space.

UV

Ignores the third dimension in texture space.

UVPelt creates the UV texture attribute if it does not already exist. The attribute class (Vertices or Points) is determined by the Target Type. It is recommended that UVs be applied to vertices, since this allows fine control on polygonal geometry and the ability to fix seams at the boundary of a texture.

Note

UVPelt only operates on polygons. Other geometry type such as Bezier and NURBS surfaces can be converted to polygons using a Convert operation prior to applying UVPelt.

Using UV Pelt

  1. Click the UV Pelt tool on the Texture tab.

  2. Select the edges that will form the boundary of the pelt.

    Note

    Press F to select the next edge in the direction indicated by the arrow. Press L to select a loop. Press ⇧ Shift + R to reverse the arrow direction.

  3. Press Enter to unwrap your selection.

You can scale the pelt by increasing the Boundary Springs in the parameter editor. You can also use UV Edit to move the UVs.

Parameters

Group

Edges to cuts.

Target Type

The attribute class (Verticies or Points) that will receive the UV attributes.

Create Output Group

Indicates a primitive group should be created for the polygons making up the the pelt.

Output Group

Name of the primitive group to create.

Pelt

Iterations

Specifies the number of iterations of the algorithm for solving the UV positions.

Boundary Springs

The strength of the springs connecting the pelt boundary to the frame.

Stiffness Attribute

Specifies an attribute of the input geometry’s points that will be used to scale the strength of the springs connected to the point.

Hint Primitive

The primitive specifying which section of the geometry forms the pelt.

Frame

Frame

The primitive to use for the frame.

U From

The attribute of the frame used for the U coordinate.

V From

The attribute of the frame used for the V coordinate.

Use Range

Indicates the UV coordinates should be moved to the ranges specified with U Range and V Range.

U Range

The location of the left and right edges, respectively, of the texture

V Range

The location of the bottom and top edges, respectively, of the texture

Orientation

Specifies where on the frame to position the first boundary point (the boundary point closest to the hint polygon).

Weight Attribute

Specifies an attribute of the frame’s points that will guide the process of connecting boundary points to the frame.

Examples that use this node

Example forExample name
MaterialLoad | Launch

.../examples/nodes/shop/material/DownHillLavaFlow.otl

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