Setting explosion start and end times for Fire_Effect

The start and end spinners in the Explosion Setup dialog for Fire-Effect effectively install keyframes and set times and values for them in the controller for phase. You can achieve the same effect by manually constructing a phase controller and its keyframes. In the following example, the start and end times are set at 20 and 75:

EXAMPLE

c = fire_effect density:20 outer_color:red
-- to set up a new phase controller like the setup dialog does:
-- make and set the controller
pc = bezier_float ()
c.phase.controller = pc
-- add key 1 at 20 & set properties
k = addNewKey pc 20
k.value = 0
k.inTangentType = #slow
k.outTangentType = #fast
-- add key 2 at 75 & set
k = addNewKey pc 75
k.value = 300
k.inTangentType = #slow
k.outTangentType = #fast
-- or, to change times if the keys are already there:
c.phase.keys[1].time = 20
c.phase.keys[2].time = 75