This operator computes a number between zero and one. The return code is 0 if the amount passed in is less than or equal to the first value, 1 if the amount is greater than or equal to the second value. If the amount is within range, a smooth (easin/easeout) interpolation is computed.
If a rolloff is specified, the inflection point of the blend will be shifted. If the rolloff is greater than 1, the shift will be to the right. If the rolloff is less than 1 (and greater than 0), the shift will be to the left.
The following examples include this node.
This example demonstrates how to diffuse the density of a smoke simulation using the Gas Diffuse DOP.
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.
Most of the parameters for the lava material are overridden by point attributes created in the surface nodes.
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.
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.
This example illustrates how custom shaders can be used to define the appearance of fur generated by the Fur SOP.