Houdini 17.0 Nodes VOP nodes

Mix VOP node

Computes a blend (or a mix) of its input values using linear interpolation.

This operator computes a blend (or a mix) of its input values using linear interpolation. If the bias specified is outside the range 0 to 1, the values will be extrapolated linearly.

This operator performs the same function as the VEX lerp() call. For a filtered, three-way blend, see Blend Regions.

Examples

The following examples include this node.

FlipColumn Example for FLIP Solver dynamics node

This example demonstrates how a mixture of fluid colours can have their colour changed by a collision with a static object.

FlipFluidWire Example for FLIP Solver dynamics node

This example demonstrates the use of the Flip Solver and the Fluid Force DOP. The Fluid Force DOP is used to apply a drag force on a wire object according to the motions of a flip fluid. The drag force is only applied at locations where fluid exists in the fluid object.

grass

This example simulates grass being pushed down by an RBD object. Fur Objects are used to represent the blades of grass and Wire Objects are used to simulate the motion. When a single Fur Object is used to represent the grass, neighbouring blades of grass will have similar motion. Additional objects with different stiffness values can be used to make the motion less uniform. When "Complex Mode" is enabled, two objects are used to represent the grass. The stiffness of each set of curves can be controlled by adjusting the "Angular Spring Constant" and "Linear Spring Constant" parameters on the corresponding Wire Objects.

FluidGlass Example for Particle Fluid Solver dynamics node

This example demonstrates how to get a smooth fluid stream to pour into a glass.

Down Hill Lava Flow Example for Material shader node

In this file we create a downhill lava flow with crust gathering and hardening at the base of the slope. All of the animation is achieved through the shader itself, and all of the geometry is completely static.

Note

Most of the parameters for the lava material are overridden by point attributes created in the surface nodes.

FirePit Example for Material shader node

Note

No geometry is animated in this file. All animation is achieved by animating the textures

Flames are grids so that UV textures can easily be applied, they are then warped around a metaball using a magnet SOP. The flames are then assigned to either a yellow or blue Flames texture. The Flames' opacity mask wrap is set to Decal to prevent the texture from repeating and showing a single pixel ring at the top of the flame geometry. I'm also using a mask file named flameOpacMap.jpg to enhance the flames' shape at the top. The noise offset has been animated over $T with an greater emphasis on the Y axis so that the flames look like they are rising. This is the same reason the Noise jitter is larger for the Y axis as well.

The coals are spheres that have been copy stamped onto a deformed grid. Using Attribute Create surface nodes I am able to override and copy stamp the lava texture’s parameters at the SOP level so that local variables, such as $BBY, can be used to animate the texture. This way the texture’s crust and its crust values can be used only to form the tops of the coals. This reserves the lava aspect of the texture to be used on the bottoms of the coals. The lava intensity (Kd attribute) is then stamped and animated to create the look of embers on the bottom of coals glowing.

Clumping Example for Fur geometry node

The Fur SOP is used to instance hair-like curves.

In this case, the Fur SOP is used to create curves that can be used for clumping. A second Fur SOP is used to illustrate how to create hairs that use the clumping geometry.

FurBallWorkflow Example for Fur geometry node

This example demonstrates how the Fur SOP and Mantra Fur Procedural can be applied to an animated skin geometry. CVEX shaders are used to apply a custom look to the hairs based upon attributes assigned to the geometry.

FurPipelineExample Example for Fur geometry node

This example illustrates how custom shaders can be used to define the appearance of fur generated by the Fur SOP.

Shaved Example for Fur geometry node

This example demonstrates how to use a texture to control hair density.

AlphaOmega Example for Points from Volume geometry node

This example demonstrates how to use a Points From Volume SOP to create a target goal for a flip simulation and make it fill a given piece of geometry.

See also

VOP nodes