field.ramp (procNode)

A ramp read at every element by a value it carries: a particle's colour, size or opacity following its age. It takes the value each element reads by (the wired t, else the element's own by attribute, through value.fallback and field.attribute), maps it from range onto 0..1 (field.map_range, the ends read off range by value.get), and reads the ramp there with ramp.sample, compiled into the element's dispatch. A value past either end of range reads that end of the ramp.

Inputs

• ramp (Ramp): the ramp to read.
• t (Field<Float> | Float): where along the ramp each element reads. Unwired, it is the element's own by attribute.
• by (String, default "life"): the Float attribute each element reads the ramp by when t is unwired. A particle solver's particles carry life, 0 at birth to 1 at death.
• range (Vec2, default { 0, 1 }): the values of t that land at 0 and at 1 on the ramp, so a speed from 0 to 20 or a temperature from 300 to 3000 reads the whole ramp.

Outputs

• field: the ramp's value at each element.

Which graph calls it

This node is built with proc.graph and g:node, and a proc.graph graph calls it as g:node("<id>", "field.ramp", ...). A graph built with proc.define calls g.field.ramp in its place, the node written in the call form; g.op.field.ramp there is refused, naming it.