Houdini 17.0 Nodes VOP nodes

Add Constant VOP node

Adds the specified constant value to the incoming integer, float, vector or vector4 value.

This operator adds the specified constant value to the incoming integer, float, vector or vector4 value.

It represents a simpler version of the Add operator because it does not require a second input. It is ideal as an increment (i++) operation in a While loop.

Examples

The following examples include this node.

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.

repeatsmooth

This example uses the foreach sop to apply the same SOP repeatedly to the geometry, accumulating the effect of each pass.

PointCloudIterateAverage Example for Point Cloud Iterate VOP node

This example shows how the pciterate vop can be used to average together points returned by pcopen. First, a point cloud is generated with a floating point "check" channel initialized to 1 inside a circle in the x-z plane. Then, the points are filtered in a shader by looping using the pciterate vop and averaging the value of the "check" channel. The point cloud used in the example is stored inside the asset as points.pc.

PointCloudLookup Example for Point Cloud Iterate VOP node

This example shows how to accomplish point cloud lookups for volumes using pcfilter and pciterate. It demonstrates how to iterate over and import values returned by a query.

See also

VOP nodes