Shaders

Noise shaders

These shaders use the RenderMan noise function to vary the color and displacement of surfaces. These shaders are very flexible, with controls for scaling noise, color

The first shader, colornoise, applies surface color.

The second shader, displacenoise, displaces the surface.

Parameters used in colornoise.sl and displacenoise.sl

Parameter	Data Type	Usage	Example
noisetype	float	The type of noise function used 0 = t wrap 1 = s wrap 2 = s,t wrap 3 = x,y,z (object space)	noisetype = 3
offsetX, offsetY, offsetZ	float	The offset in the noise lattice	offsetX = 0
scaleX, scaleY, scaleZ	float	The scale in the noise lattice	scaleX = 1
scaleRed, scaleBlue, scaleGreen	float	The scale for color channels. (Note: for displacenoise.sl, the sum of scaleRed, scaleGreen and scaleBlue should equal three).	scaleRed = 1, scaleBlue = 1, scaleGreen = 1

Additional parameters used in colornoise.sl

Parameter	Data Type	Usage	Example
shadingType	integer 0 to 5	The shading method code 0 = constant 1 = constant 2 = plastic 3 = matte 4 = glow (use on sphere) 5 = halo (use on sphere)	shadingType = 0
Ks, Kd, Ka	float	The usual meanings	Ks = 1
roughness	float	Roughness value for plastic shading method	roughness = 0.1
attenuation	float	For glow and halo methods	attenuation = 2
specularcolor	color	For plastic shading method	specularcolor = (1, 1, 1)

Additional parameters used in displacenoise.sl

Parameter	Data Type	Usage	Example
Km	float	Maximum displacement	Km = 1

View the colornoise shader source

View the displacenoise shader source

Download the noise shader package for Presenter 3D