So I've been searching around this site, and it has striked me that I haven't discovered to much on EFX files.

Im just interested in some things that confuse me in these EFX, more specifically this barreloil_fire.efx

Particle
{
	name				smoke

	flags				setShaderTime useAlpha

	spawnFlags			evenDistribution rgbComponentInterpolation

	count				0 1

	life				1250 3000

	delay				0 300

	cullrange			4000

	origin				30 -5 -5 50 5 5

	radius				60 50

	wind				95 100

	rotation			-15 15

	rotationDelta		-1 1

	velocity			13 -2 -2 17 2 2

	acceleration		0 -2 -2 0 2 2

	rgb
	{
		end				0 0 0
	}

	alpha
	{
		start			0.35 0.5
		end				0
		parm			0.25 0.5
		flags			linear
	}

	size
	{
		start			5 8
		end				20 30
		flags			linear
	}

	shaders
	[
		smoke/smk_p_top_blk_a
		smoke/smk_p_top_blk_b
		smoke/smk_p_top_blk_c
	]
}

Is there a refence for what the flags are, or when there are triple spaced digits after something like start.

What defines the picture for the EFX?
Can 3D models be used?
Why do you need a name?

hmm, maybe someone should throw up a tutorial for them

Flags determine how a particle will behave, some examples are UsePhysics, useAlpha, Relative. Relative links the effect to whatever it is being played on, such as a weapon tag.

Triple spaced digits? not sure what you mean...

The picture is defined in the shaders[] part of the file, for example, smoke/smk_p_top_blk_a refers to a file in pk3/fxshaders/something.shader, which will have a smoke/smk_p_top_blk_a definition there somewhere, which links to an actual image file and determines it's blending, etc.

Models can be used, as shown here:

Emitter
{
	flags				useModel

	life				1000


	size
	{
		start			0
		end			1
		flags			linear
	}

	alpha
	{
		start			1
		end			1
		flags			linear
	}

	models
	[
		xmodel/h_teambubble
	]
}

This makes the xmodel 'teambubble' start with a size of 0, then increase over it's life (1000 = one second) until it reaches it's full size of 1 (100%). If there is more than one model defined, or in your case, more than one shader defined, it uses a random one.

If, by a name, you refer to the Particle at the top of the file, then that is what decides it's main behaviour. You can have several names:

Particle
Flash
Camerashake
Fxrunner
Line
OrientedParticle
Decal
Emitter
Electricity
Cylinder
Sound
Tail

Thanks for the explaination.

What I meant by the triple digits (bad question) is after things like

	life				1250 3000

why is there a space?

The amount of space isn't important, it could be:
life 1250 3000
this means it will have a life of somewhere random between 1.25 and 3 seconds

Also, inside the Alpha, and the Size functions there is a flag with the value Linear. Is this how the start and end is reached? Is there a way to do exponential growth?

EX: (this is a graph, where the y axis is the size, and the x axis is the transition from Start to End)

|-----/ End
|----/-
|---/--
|--/---
|-/----
--------
Start

^Best i could make with ASCII art

well, linear means it will go from one value to the next steadily
nonlinear means it has like a slow acceleration, toward the end of its life it will then start to disappear (if were sayin about alpha)

oh that reminds me. Is there a way to make effects fade in then fade out? linear and nonlinear flags only go in one direction.
following one fade in fx, followed by a seperate one that fades out always creates a noticeable seam/overlap

yeah, you could make the first particle go from 0 to 1, then add another particle to the fx (delay 1000 or whatever the life of the first one is) and make that fade from 1 to 0

that's what i did, but theres always a flicker between the two shaders/particles - either overlapping (so they become less translucent), or not showing for that fraction of a second. It might nnot happen for small life/delay values, but it's very noticeable once you start using e values

Here are all the flags
lessAttenuation
affectedByWind
rgbComponentInterpolation
evenDistribution
randrotaroundfwd
axisFromSphere
orgOnCylinder
orgOnSphere
oppositeRotation
oppositeAccel
absoluteAccel
absoluteVel
cheapOrg2Calc
cheapOrgCalc
org2isOffset
traceImpactFx
org2fromTrace
clampRotation
clampVelocityZ
clampVelocityY
clampVelocityX
clampVelocity
continualLighting
setShaderTime
relative
depthHack
emitFx
useAlpha
deathFx
impactFx
impactKills
expensivePhysics
usePhysics
useBBox
useModel


clamp
random
wave
nonlinear
linear