Prman Global Variables And User-Defined Variables

Front 1

P*

Back 1

Point
Varying
Surface Position
R/W enabled

Front 2

dPdu

Back 2

vector
varying
Derivative of surface position along u

Front 3

dPdv

Back 3

vector
varying
Derivative of surface position along v

Front 4

N*

Back 4

normal
varying
Surface shading normal
R/W enabled

Front 5

Nn+

Back 5

normal
varying
Normalized Surface shading normal
normalize(N)

Front 6

Ng

Back 6

Surface geometric normal

Front 7

I (i)

Back 7

vector
varying
Incident ray direction
a vector that travels from eye to the surface point

Front 8

E

Back 8

point
uniform
Position of the Eye

Front 9

u,v

Back 9

float
varying
Surface parameters

Front 10

du, dv

Back 10

float
varying
Change in surface parameters

Front 11

s,t

Back 11

float
varying
Surface texture coordinates

Front 12

ss,tt
sss,ttt
ssss,tttt
etc

Back 12

float
varying
(Any) Modification to surface texture coordinates

Front 13

ncomps

Back 13

float
uniform
Number of color components

Front 14

time

Back 14

float
uniform
Current shutter time

Front 15

dtime

Back 15

float
uniform
The amount of time covered by this shading sample

Front 16

IOR+

Back 16

float
uniform
Index of refraction for a material

Front 17

eta+

Back 17

float
uniform
The ratio of the index of refraction IOR In the volume containing the incident vector to that of the volume being entered.

Front 18

V+

Back 18

vector
varying
-normalize(I);
The normalized vector traveling from position of the viewer's "eye" to surface point
USED TO: _____

Front 19

ceiling( v )

Back 19

float
Smallest integer >= v

Front 20

floor( v )

Back 20

float
Largest integer <= v

Front 21

round( v )

Back 21

float
Closest integer to v

Front 22

K-anything+

Back 22

RSL has German origins so anytime a coefficient is used for a part of code, it's noted with a K - instead of a C - because coefficient is spelt "Koeffizient", auf Deutsche.

Front 23

T+

Back 23

Frequently used to note a vector. It has a couple of other uses but I need to learn more before I write it down.

Front 24

Km+

Back 24

float
uniform(?)
A stored value for the calculated displacement bound of a shader.