Standard Shaders
Standard Shaders
Standard RenderMan Interface Shaders
Null Shader
This shader does nothing and is intended to be a placeholder if no action is to be performed. There is a null shader for every class of shader.
Surface Shaders
Constant surface
surface
constant ()
{
Oi = Os;
Ci = Os * Cs;
}
Matte surface
surface
matte (
float Ka = 1;
float Kd = 1;)
{
normal Nf = faceforward (N, I);
Oi = Os;
Ci = Os * Cs * (Ka * ambient () + Kd * diffuse Nf));
}
Metal surface
surface
metal (
float Ka = 1;
float Ks = 1;
float roughness =.1;)
{
normal Nf = faceforward (N, I);
vector V = -normalize (I);
Oi = Os;
Ci = Os * Cs * (Ka * ambient () + Ks * specular (Nf, V, roughness));
}
Shiny metal surface
surface
shinymetal (
float Ka = 1;
float Ks = 1;
float Kr = 1;
float roughness = .1;
string texturename = ""; )
{
normal Nf = faceforward (N, I);
vector V = -normalize (I);
vector D = reflect (I, normalize (Nf));
D = v transform ("current", "world", D);
Oi = Os;
Ci = Os * Cs * (Ka * ambient () + Ks * specular (Nf, V, roughness)
+ Kr * color environment (texturename, D));
}
If the Environment Mapping capability is not supported by a particular renderer implementation, the shinymetal surface shader operates identically to the metal shader.
Plastic surface
surface
plastic (
float Ka = 1;
float Kd =.5;
float Ks =.5;
float roughness =.1;
color specularcolor = 1;)
{
normal Nf = faceforward (N, I);
vector V = -normalize (I);
Oi = Os;
Ci = Os * (Cs * (Ka * ambient () + Kd * diffuse (Nf)) +
specularcolor * Ks* specular (Nf, V, roughness) );
}
Painted plastic surface
surface
paintedplastic (
float Ka = 1;
float Kd = .5;
float Ks = .5;
float roughness = .1;
color specularcolor = 1;
string texturename = "";)
{
normal Nf = faceforward (N, I);
vector V = -normalize (I);
Oi = Os;
Ci = Os * (Cs * color texture (texturename) *
(Ka * ambient () + Kd * diffuse (Nf)) +
specularcolor * Ks * specular (Nf, V, roughness));
}
If the Texture Mapping capability is not supported by a particular renderer implementation, the paintedplastic surface shader operates identically to the plastic shader.
Light Source Shaders
Ambient light source
light
ambientlight (
float intensity = 1;
color lightcolor = 1;)
{
Cl = intensity * lightcolor;
}
Distant light source
light
distantlight (
float intensity = 1;
color lightcolor = 1;
point from = point "shader" (0,0,0);
point to = point "shader" (0,0,1);
{
solar (to-from, 0.0)
Cl = intensity * lightcolor;
}
Point light source
light
pointlight (
float intensity = 1;
color lightcolor = 1;
point from = point "shader" (0,0,0); )
{
illuminate (from)
Cl = intensity * lightcolor / L.L;
}
Spotlight source
light
spotlight (
float intensity = 1;
color lightcolor = 1;
point from = point "shader" (0,0,0);
point to = point "shader" (0,0,1);
float coneangle = radians(30);
float conedeltaangle = radians(5);
float beamdistribution = 2;)
{
float atten, cosangle;
uniform vector A = (to - from)/length (to-from);
illuminate (from, A, coneangle) {
cosangle = L . A / length (L);
atten = pow (cosangle, beamdistribution) / L.L;
atten *= smoothstep (cos(coneangle),
cos (coneangle - conedeltaangle), cosangle);
Cl = atten * intensity * lightcolor;
}
}
Volume Shaders
Depth cue shader
volume
depthcue (
float mindistance = 0, maxdistance = 1;
color background = 0;)
{
float d;
d = clamp ((depth(P) - mindistance) /
(maxdistance - mindistance), 0.0, 1.0);
Ci = mix (Ci, background, d);
Oi = mix (Oi, color(1, 1, 1), d);
}
Fog shader
volume
fog (float distance = 1; color background = 0;)
{
float d;
d = 1 - exp (-length (I) / distance);
Ci = mix (Ci, background, d);
Oi = mix (Oi, color(1, 1, 1), d);
}
Displacement Shaders
Bumpy shader
displacement
bumpy (
float Km = 1;
string texturename = "";)
{
float amp = Km * float texture (texturename, s, t);
P += amp * normalize (N);
N = calculatednormal (P);
}
If the Bump Mapping capability is not supported by a particular renderer implementation, the bumpy surface shader is equivalent to a null displacement shader.
Imager Shaders
Background shader
imager
background ( color background = 1; )
{
Ci += (1-alpha) * backaground;
Oi = 1;
alpha = 1;
}