This example shows how to create an atmosphere shader with volumetric shadows. The atmosphere object has a vex lit fog shader attached to it, and the spotlight has deep shadows enabled. The objects in the scene have a matte shader attached to them.
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.
RIS Shader Network
Mantra: VEX Volume Procedural
This example shows how to render an isosurface defined by a cvex shader using mantra’s volume rendering capabilities. A noise field is generated by a cvex shader, which is attached to the VEX Volume Procedural. The volume is shaded by finding the surface where the density crosses 0, and then shading using a simple surface shader that shows the normals.