Houdini 20.5 Nodes Geometry nodes

PolyFill geometry node

Fills holes with polygonal patches.

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Since 16.0

Using PolyFill

  1. Select at least one edge in each hole you want to fill.

  2. Click the PolyFill tool on the Polygon tab.

Tips

  • The Quadrilaterals fill mode is most useful for filling in small groups of polygons, and can handle a wider variety of shapes, such as an L-shaped hole or a spiral.

  • The Perfect Grid Quadrilaterals fill mode can handle fewer shapes, but often generates a better patch with better interpolated attributes.

  • If you are filling in a round hole, the Perfect Grid Quadrilaterals fill mode will likely give you the best results.

  • Some holes may require additional smoothing to fix UV values. You can use the Smooth parameter to position the geometry where you like, then append a UV Smooth to fix the UV values separately.

  • If a projection plane normal cannot be found for your geometry, you may want to use the Clean SOP to clean up your geometry first, especially consolidating points.

Note

Each patch is automatically fused to the boundary; however, there is an option to turn on the Unique Points checkbox in the parameter editor.

Parameters

Boundary Group

A list of boundary edges which define the holes to be filled. If this group is empty, all holes in the input geometry will be filled.

Fill Mode

The algorithm used to fill the holes.

Single Polygon

Fills each hole with a single polygon connected to all of the points in the hole.

Triangles

Fills each hole with triangles. This is the same as filling with a single polygon, then applying a Divide with Don’t Generate Slivers and Avoid Small Angles on.

Triangle Fan

Places a point in the center of the hole and connects it to each point on the boundary of the hole.

Quadrilateral Fan

Places a point in the center of the hole and connects it to every other point on the boundary of the hole.

Quadrilaterals

Fills each hole with quadrilaterals by mimicking how a human might do it. It searches for U shaped holes to fill with an extra edge. If none can be found it searches for L shaped sections instead, which are filled by generating a perfect parallelogram. It prefers to add the next quad in the vicinity of last one. This typically gives the best results if Smooth is on.

Quadrilateral Grid

Fills each hole with quadrilaterals in a topologically perfect grid. This typically gives the best results if Smooth is off.

Auto-Complete Boundaries

Find the rest of each hole when the boundary group only contains part of a hole. Turning this off allows you to select, say five edges of a hole, and the patch will only cover those five edges, not the entire hole.

Reverse Patches

Reverse the orientation of the created polygons.

Unique Points

Create patches with their own points.

Update Point Normals

Recompute point normals, if they exist.

Edge Loop

Create an edge loop around each hole at the given percentage along each edge. If Smooth is on, the position of the edge loop is generated after any smoothing occurs.

Smooth

Smooth the attributes on the patches. This is the same as applying a smooth with the given strength.

Corner Offset

Rotates the corners of the quads generated by the Perfect Grid Quadrilaterals and Quadrilateral Fan fill modes.

Custom Corners

A point group which specifies which boundary points should be corners of quads. In the Quadrilateral Fan fill mode, a single corner can be chosen to determine where the fan is generated, as there are only two possibilities to fill in each hole. In the Perfect Grid Quadrilaterals fill mode, at least two adjacent corners of the grid must be included in this group for each hole you want to choose corners for. If a hole has no points in this group, the most suitable corners will be automatically detected.

Deform Patch

Allows the patch to be deformed from its default position. The Triangle Fan and Quadrilateral Fan fill modes can be extruded with the Surface Offset parameter. The Perfect Grid Quadrilaterals fill mode creates a smooth perfect grid which can be made to follow the surface of the surrounding geometry with the Surface Offset and Tangent Strength parameters.

Surface Offset

The distance to stretch the patch.

Tangent Strength

How strongly the patch follows the surrounding geometry.

Patch Group

A group that contains the primitives in the interior of the patch.

Edge Loop Group

A group that contains the primitives adjacent to the edge loop.

Append to Groups

If a group already exists with the given name, add the primitives to that group instead of replacing it.

See also

Geometry nodes