Houdini 20.0 Nodes Geometry nodes

Group Paint geometry node

Sets group membership interactively by painting.

The Group Paint SOP lets you use a brush over points to add them to or remove them from a point group.

If the group specified does not exist, then this SOP creates it.



Point Group

The point group to be affected by the paint operation.


The operation performed by the brush when painting.

Add Points

Adds the painted points to the group.

Remove Points

Removes the painted points from the group.

Accumulate To Stencil

See about accumulate to stencil . By default, the operation is applied and the stencil cleared after every brush stroke. When this option is on, Houdini does not apply the stencil until you click Apply and Clear Stencil.

Apply & Clear Stencil

Applies the operation and clears the stencil. This is equivalent to right-clicking in the viewport.

Reset All Changes

Restores the selected group to its initial state.

Visualize Attribute

Whether to do a false color visualization of what points are currently included in the specified point group.

Visualize Mode

How to map group inclusion to a color.



The basic shape of the brush: circle or square.


The radius of the brush when painting in the 3d viewport

Brush Angle

How far to rotate the brush.

Brush Squash

Amount to squash the brush in the y direction before rotation.



If set, the brush will perform reflective symmetry. Any strokes will be mirrored along the plane of symmetry.


If set, the brush will perform rotational symmetry. Any strokes will be rotated around the axis of symmetry.


This defines the normal of the plane of symmetry for reflection and the axis of symmetry for rotation.


This defines the origin of the plane of symmetry for reflection and the origin of the axis of symmetry for rotation.

Number of Rotate

This defines the degree of rotational symmetry. A degree of 3 means the stroke will be applied 3 times at 120 degree separation. A value of 5 will perform the stroke 5 times with 72 degrees of separation.

Reflection Dist

This is the distance of the plane of symmetry from the origin of symmetry.

UV Reflection

If set, the brush will reflect when brushing is done in the UV viewport.

UV Origin

The origin of the line of reflection in the UV viewport.

UV Angle

The angle of the line of reflection in the UV viewport. 0 will mirror about the U axis, 90 will mirror about the V axis.


Orient Brush to Surface

Switches between the brush being perpendicular to the surface or always oriented along the view direction. If you are having trouble with a shaky brush, try turning this off.

Use Connectivity

If set, the tool will only affect points connected to the closest point to the intersection. This is usually a good thing, as it avoids accidentally painting through the geometry (but see the depth parameter), but can prevent smoothly painting across seams.

Use Normals

If set, the tool will only affect points facing in the same direction as the closest point to the intersection. This is usually good to avoid accidentally painting the backfacing parts of geometry, but if you want a pure depth brush can be turned off.

Realtime Mode

Set this to paint geometry as it’s deforming.


The current direction of the brush. If orient to surface is on, this is the normal direction of the surface hit by the brush. Otherwise, it is the direction from the eye to the surface.

Hit Location

The current location of the brush. This tracks the surface as the brush moves along it.

Hit Primitive

The primitive number of the primitive the current brush is centered at.

Hit UV

The location the current brush is on the current primitive. Note this is a parametric UV location, not the texture UV location.

Hit Pressure

The amount of force the brush is currently applying. This is only meaningful when a tablet interface that supports pressure is used.

Hit Point

The point closest to the current brush’s center.


Controls the current state of the brush. When it is on No-op, the values of the stroke tab are ignored and no updating of the geometry is done. Other values are set automatically as you brush the surface, allowing the SOP to update in response to your actions.

See also

Geometry nodes