Descr effects torch fire.txt

Descr_effects_torch_fire.txt is used in BI to determine the effects used for torches in night battles. M2TW has a similarly structured file called descr_torch_fire.txt.

soldier_torch_fire

This section is an examination of what changes to one particular section do, other sections are similar in many respects so the information should be useful for other parts. Vanilla section:

effect soldier_torch_fire
{
	 type particle
	{
		texture				battlefield/fire/#flame_wheel.tga		
;		texture				models_effects/textures/checker_board.tga
		sprite_origin		0.0, 0.0
		sprite_size			1.0, 1.0

 		size_range       	0.1, 0.1
		age_range        	0.3, 0.3
	    grow_range		 	1.0, 1.0
		vel_range  			0.6, .6
		
		keyframe_colour
		{
;				0.0		255, 255, 255, 255
				0.0, 	0,   236, 242,     0
				0.1, 	255, 236,  242,   0
				0.5, 	255, 236,   149,   22
	 			1.0, 	0,   255,   149,   22
		}
		
		alpha_max	   		255			 ; maximum alpha value
		initial_size		0.2, 0.5
		blend_type			additive
		offset				0.0, 0.0, 0.2
		max_particles       3000

		emitter distance_time
		{
			density			        200 	   	; how many particels per second
			emitter_falloff_dist	100			; distance in meters to reduce emission over
			emitter_falloff_bias	0.5			
			distance_scale  		1
			max_distance			0.2	
			age_scale				0.45		
		}

		random_emit_radius		0, 0.1
		system_radius			2.0			    ; radius used for culling
		batched
	}
}

Above screenshot shows the torch flame effect created by the vanilla file (units shown are by Halie Satanus for the Lycan Rising mod). The tendency for the fire effect to intersect with curved shields can be seen on the unit in the background.

sprite_origin

Messing with sprite origin doesn't do anything useful, leave as 0,0

sprite_size

Normal setting is 1.0, 1.0 (for BI) - changing this can produce some strange effects especially using non-equal values, reducing to 0.1, 0.1 makes the sprite more or less disappear, see below:

incidentally you can see in that picture that with the fire effect removed you still have a glow from the torch model, that actually seems to account for the lighting cast onto the units and not the fire effect.

size_range

Normal setting is 0.1, 0.1 - making either number a lot larger increases the flame size appreciably, its not clear from experimentation quite what each individual number does. Making both numbers a lot smaller, eg 0.003, 0.003 doesn't seem to have any effect.

age_range

Normal setting is 0.3, 0.3, increasing these settings makes the fire starting at the torch travel further before disappearing, it can also mean that the fire forms as a sort of bubble at the torch and then floats away from it! Higher values for this line are used for the smoke effects, where they clearly make more sense. Changing them for the fire effect doesn't seem helpful.

grow_range

Initial values are 1.0, 1.0 - increasing to 5.0, 5.0 produces a much larger flame with white center when the unit is moving (not recommended). Reducing the values to 0.1 etc doesn't have much apparent effect.

vel_range

Initial values are 0.6, .6, much smaller values center the fire effect lower on the torch and 'burn' the holders hand. High values produce a much higher and faster moving flame, of little practical benefit except it does allow you to see how the constituent colours of the flame are working see keyframe-colour section below.

keyframe_colour

Using higher vel_range values and making the colours more extreme shows how the different colour components go together, (screenie is taken after adjusting some values that influence colour, hence the appearance of the green section):

confusingly there appear to be four colours against each line and not the normal three for RGB values, eg:

0.5,    255, 236,   149,   22

Testing with extreme colour values and the high vel_range settings show how this section breaks down.

Image is screen-shot taken with the current section of file visible on top after alt-tabbing out of game. (This seems to be a useful method of testing as it keeps permanent record of appearance versus file content, which can be quite hard to remember if you just try and write down results.)

Explanation:

First number on line represents approximate percentage distance from source that the colour ends, colour on line below starts after that.

Second number on line influences colour intensity - this is partly counteracted by other factors giving higher density closer to source.

Third number = red content (standard RGB notation 255 = max)

Fourth number = green content

Fifth number = blue content

alpha_max

Initial value 255 - no apparent effect if changed

initial_size

Initial value in vanilla file 0.2, 0.5 - making larger does the relatively obvious and is not attractive. Reducing the values makes the initial size of the flame smaller but it still seemigly grows as large when the unit starts to move.

blend_type

Initial value = additive - no idea what other values would be so not experimented with

offset

Initial value = 0.0, 0.0, 0.2 - changing these values moves the flame in relation to the torch held by the unit. For the first number an increase moves the flame towards the back of unit, the second number increasing moves the flame to the right (when viewing from front), the third moves the flame upwards.

max_particles

Initial value = 3000 - a lot lower number (eg 100) makes flame smaller and flash on and off, larger doesn't seem to make much difference.

random_emit_radius

            0, 0.1

system_radius

                 2.0                         ; radius used for culling
               batched