Houdini 20.0 Nodes Geometry nodes

RBD Interior Detail geometry node

Creates additional detail on the interior surfaces of fractured geometry.

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Since 17.0

This SOP creates additional detail on the interior surfaces of fractured geometry, which can be used to produce more interesting high resolution geometry. The amount of noise added to the points can be scaled based on their distance from the original surface.

Tip

The Transform Pieces SOP can be used to transform high resolution pieces according to the motion of simulated low resolution pieces.

Inputs

Geometry

The geometry to add interior detail to.

Constraint Geometry

Optional input to pass through constraint geometry (for example, from the Voronoi Fracture SOP).

Proxy Geometry

Optional input to pass through proxy geometry.

Optional SDF for Depth Sampling

An optional SDF Volume, usually created by IsoOffset, to use for depth sampling when scaling the amount of noise added to the geometry. If not connected, this node will generate a default one.

Outputs

Geometry

The high-resolution geometry.

Constraint Geometry

The constraint geometry from the Constraint Network input.

Proxy Geometry

The geometry from the Proxy Geometry input, or the original Geometry input if no proxy geometry already exists.

Parameters

Interior Group

Specifies the primitives to add detail to. Typically, this group should contain only the interior polygons created by the fracturing process so that the original surface is not affected.

Geometry

Add Detail

Specifies whether the interior surface should be divided according to the Detail Size. Disabling this allows noise to be applied to interior surfaces that do not need any further subdivision.

Detail Size

The size of the polygons added to the interior surfaces.

Compute Interior Normals

Computes vertex normals on the edges of the interior geometry, so that they will have a cusped appearance.

Interior Cusp Angle

Computes vertex normals on the edges of the interior geometry with angles greater than this angle, so that they will have a cusped appearance.

Triangulate Non-Planar Detail

Triangulates any non-planar polygons produced while adding detail.

Noise Settings

Noise Amplitude

Scales the amount of displacement.

Noise Type

The type of noise added to the interior points.

Frequency

The frequency of the noise. Higher values give smaller scaled details in the noise.

Offset

The offset of the input into the noise function. If you visualize the noise as a 2D graph or 3D height field, this has the effect of “panning” across the space of possible noise outputs. If you have the general noise effect you want but just want to get a different set of values for a different look, try changing the offset.

Fractal Type

None

Does not add any additional noise on top of the basic noise.

Standard

Adds pseudo-random noise on top of the basic output.

Terrain

Adds noise like “Standard” but dampens the noise in the valleys, which can be useful for generating mountainous terrain.

Hybrid

Like terrain, but with more sharpness in the valleys.

Max octaves

The number of iterations of distortion to add to the output of the basic noise. The more iterations you add, the more “detailed” the output. Note that the output may have fewer octaves than this parameter (that is, increasing the parameter will eventually stop adding detail), because the node eventually stops when there’s no more room to add more detail in the output.

Lacunarity

The frequency increment between iterations of fractal noise added to the basic output. Note that you can use a negative value.

Roughness

The scale increment between iterations of fractal noise added to the basic output. The higher the value the larger the “jaggies” added to the output. You can use a negative value for roughness.

Enable Lattice Warp

Adds “stringiness” or “wiriness” to standard noise.

Accumulate Lattice Warp

When Lattice Warp is on, this accumulates the warp for each iteration (octave) of added fractal noise. When used in images, this can add interesting smudgy effects, and interesting landmarks when used for terrain.

Enable Gradient Warp

Enables a slider to widen the peaks or valleys of the noise output.

Accumulate Gradient Warp

When Enable Gradient Warp is on, this accumulates the warp for each iteration (octave) of added fractal noise.

Displacement Scaling

Visualize Noise Scale

Adds color to the geometry to indicate the amount of noise applied at each point.

Depth Method

Specifies how to compute the distance of each interior point from the surface.

Minimum Distance to Exterior

Computes the minimum distance from each interior point to the exterior primitives, similar to the Ray SOP’s Minimum Distance method. Compared to the SDF Volume method, this approach does not require selecting a suitable volume resolution and can be faster than building a high resolution volume.

Note

This method does not produce accurate distances if the points in the Interior Group are not actually inside the surface of the original geometry, or if the original geometry is self-intersecting.

SDF Volume

Computes the depth by sampling an SDF volume. The volume is built from the input geometry using the Depth Volume Resolution, unless a volume is provided via the optional fourth input.

Depth Volume Resolution

Resolution of the default depth sampling SDF. The amplitude of the noise added to the interior points is scaled by the depth of the point within the surface of the original geometry, calculated by sampling an SDF of the geometry. If an SDF is not connected to the fourth input of the SOP, a default one will be created at this resolution.

Clamp Displacement Amount to Depth

Limit the amount of displacement done at a point by its depth within the surface.

When adding high amplitude noise to the interior points, it’s possible that the interior surface could interpenetrate the exterior. This option will clamp the amount of displacement at a particular point by the depth within the surface.

Clamp Depth Percentage

The percentage of the depth within the surface to which the displacement should be clamped.

Because an SDF is not a perfect representation of depth, this option allows you to clamp to a percentage of the depth. Lowering this can guarantee no interpenetration, at the expense of more clamping of the interior noise.

Use Depth/Noise Ramp

Use a ramp control for more precise control of the depth/noise mapping.

Depth/Noise Bias

The value for the bias curve that maps depth within the surface to the amplitude of the noise applied.

Depth/Noise Ramp

The ramp that maps from depth within the surface to the amplitude of the noise applied.

Output Attributes

Point Depth

Creates an attribute containing the depth of each point within the surface of the object.

See also

Geometry nodes