This document describes the evaluation language used in the expression
parameters of the Eval* nodes.
Basic operators (+, -, *, /) are supported, as well as parenthesis.
Whitespaces (including line breaks) are allowed as well.
| Constant | Description |
|---|---|
e |
Euler's number, base of the natural logarithm |
phi |
Golden ratio |
pi |
π |
tau |
2π |
| Function | Description |
|---|---|
abs(x) |
absolute value of x |
acos(x) |
arc cosine of x |
acosh(x) |
inverse hyperbolic cosine of x |
asin(x) |
arc sine of x |
asinh(x) |
inverse hyperbolic sine of x |
atan(x) |
arc tangent of x |
atanh(x) |
inverse hyperbolic tangent of x |
cbrt(x) |
cube root of x |
ceil(x) |
smallest integral value not less than x |
clamp(x,a,b) |
constrain x to lie between a and b |
close(a,b) |
1 if a is close to b within 1e-6 relative precision, 0 otherwise |
close(a,b,p) |
1 if a is close to b within p relative precision, 0 otherwise |
cos(x) |
cosine of x |
cosh(x) |
hyperbolic cosine of x |
cube(x) |
cube of x |
degrees(x) |
convert x from radians to degrees |
eq(a,b) |
1 if a = b, 0 otherwise |
erf(x) |
error function, 2/√π * integral from 0 to x of exp(-t²) dt |
exp(x) |
base-e exponential of x (e^x) |
exp2(x) |
base-2 exponential of x (2^x) |
floor(x) |
largest integral value not greater than x |
fract(x) |
fractional part of x |
gt(x) |
1 if a > b, 0 otherwise |
gte(x) |
1 if a ≥ b, 0 otherwise |
hypot(x,y) |
euclidean distance (√(x²+y²)) |
isfinite(x) |
1 if x is finite, 0 otherwise |
isinf(x) |
1 if x is infinite, 0 otherwise |
isnan(x) |
1 if x is not a number (NaN), 0 otherwise |
isnormal(x) |
1 if x is normal, 0 otherwise |
linear(a,b,x) |
linearly remap x in range [a;b] to [0;1] |
linear2srgb(x) |
convert x from linear to sRGB (see also srgb2linear(x)) |
linearstep(a,b,x) |
saturated version of linear() (equivalent to sat(linear(a,b,x))) |
log(x) |
natural logarithm of x (see e), also called "ln" in math terminology |
log2(x) |
base-2 logarithm of x |
lt(a,b) |
1 if a < b, 0 otherwise |
lte(a,b) |
1 if a ≤ b, 0 otherwise |
max(a,b) |
maximum value between a and b |
min(a,b) |
minimum value between a and b |
mix(a,b,x) |
linearly remap x in range [0;1] to [a;b] |
mla(a,b,c) |
multiply-add in one operation (a*b + c) |
pow(a,b) |
a raised to the power of b |
print(x) |
leave x unchanged but print its value on the standard output (debug purpose) |
radians(x) |
convert x from degrees to radians |
round(x) |
round x to nearest integer, away from zero |
sat(x) |
saturate x (equivalent to clamp(x,0,1)) |
sign(x) |
1 if x is positive, -1 if is negative, 0 if zero |
sin(x) |
sine of x |
sinh(x) |
hyperbolic sine of x |
smooth(a,b,x) |
hermite interpolation (f(t)=3t²-2t³) using t=linear(a,b,x) |
smoothstep(a,b,x) |
same as smooth() but using t=linearstep(a,b,x) (only the S curve remains) |
sqr(x) |
square of x (x²) |
sqrt(x) |
square root of x |
srgb2linear(x) |
convert x from sRGB to linear (see also linear2srgb(x)) |
tan(x) |
tangent of x |
tanh(x) |
hyperbolic tangent of x |
trunc(x) |
round to integer, toward zero (see also floor()) |