CEG Definitions

Source

The engine source code which loads the tags from these files is viewable here:

Data Types

CEGs use the following data types:

You can use CEG:Operators to define floats that are not fixed.

CEG Textures

• Textures on CEG definitions are referenced by name.
• The list of available textures and their names should be in resources.lua
• Texture definitions to be used in projectile classes should be placed within the projectiletextures category and textures to be used with #CSimpleGroundFlash class should be placed within the groundfx category.
• Texture images are usually placed in the "bitmaps" subfolder.

Overall Format

A CEG file contains one or more CEGs. Each CEG follows this format:

return {
  ["ceg_name"] = {
    -- EXPLOSION LEVEL
    useDefaultExplosions = false,

    spawner1_name = {
      -- SPAWNER LEVEL
      class         = "CClassName",
      count              = 1,
      air                = true,
      ground             = true,
      water              = true,
      properties = {
        -- CLASS LEVEL
        },
      },
    },
    spawner2_name = {
      -- SPAWNER LEVEL
      -- each spawner follows the above format
    },
    groundflash = {
      -- groundflash is a special spawner name; it always generates a CStandardGroundFlash
      -- CStandardGroundFlash properties
    },
    -- other special spawner names exist, although their use is discouraged in favour of class="CSomeClass"
    -- see https://github.com/spring/spring/blob/develop/cont/base/springcontent/gamedata/explosion_alias.lua#L61
  },
}

Explosion Level Tags

Spawner Level Tags

A CEG can contain any number of spawners. The name of the spawners don't really matter, as long as it's not groundflash, which has a special meaning. You can think of each spawner as being one component of the overall explosion.

Visibility Conditions

These determine under what conditions the spawner will run. If you set the condition to true, the spawner will run if the explosion takes place under that condition. If you set more than one condition, the spawner will run if any of them are true. If you want a spawner to run only if two or more conditions are all true, you have to do a little trick with the #CExpGenSpawner class as explained in "suggested use".

Class Level Tags

Common Properties

All classes have the following properties, although not all of them use them:

CExpGenSpawner

This is the closest thing CEG has to a function call. Instead of creating a graphical effect on its own, it creates another CEG.

Suggested Use

• If you use a spawner a lot of times, you may want to make it a separate CEG to avoid having to copy-paste many times.
• This is the only way to truly delay a graphical effect.
• The spawned CEG still checks conditions, so if you want to, say, spawn an effect only if it is in water and doesn't hit a unit, you can give the CExpGenSpawner nounit = 1; and the spawned CEG water = 1;.
• This allows you to give a set of spawners the same (and possibly random) direction.
• You can animate an explosion flip-book style using delays and several bitmaps.

Properties

CBitmapMuzzleFlame

This creates three rectangular textures at right angles to each other. The has as its normal.

Suggested Use

• Muzzle flames, obviously.
• You can use an upward-pointing CBitmapMuzzleFlame as a simple splash of water or dirt.
• Railgun trails.
• This is the only class that both obeys perspective and allows for a custom texture.

Properties

CExploSpikeProjectile

This creates a glowy spike. Note that the spike is two sided, i.e., symmetric about the position of the spawner.

Suggested Use

• Anything glowy.
• For large, slow missiles, you can try using this as an extended engine flame. Set the width to something fairly large.
• Long and thin spikes will look spiky; meanwhile, shorter and wider spikes look more blobby.
• The colors of spikes add together, so if you have several spikes and all three color channels are non-zero, it will be white in the center.
• The length growth of the spike depends on the norm of the dir vector. The spike does not grow in width.

Properties

CHeatCloudProjectile

Creates an expanding sprite. Simple but effective.

Suggested Use

• As the main background to an explosion.

Properties

CSimpleParticleSystem

Creates a sprite that can undergo complex motion. Probably the most versatile class.

Suggested Use

• Anything moving that is not doing so at constant velocity.
• If you want something that expands (or shrinks) to some size then stops, set to something less than 1, and to something positive. The particle will grow to a size equal to sizeGrowth / (1 - sizeMod) and stop. The smaller is, the faster it will reach this size.

Properties

Initial Velocity Properties

Movement Properties

Size Properties

Visual Properties

Life Properties

CSpherePartSpawner

Draws an expanding sphere.

Suggested Use

• Looks like a shockwave.

Properties

CSimpleGroundFlash

Draws an expanding ground texture.

Suggested Use

• A short groundflash (~8 frames) is good for any explosion that gives off light. You can also use a longer groundflash to suggest the ground is glowing from heat.

Properties

CStandardGroundFlash

If you name a spawner "groundflash," it will always generate a standard groundflash.

Suggested Use

A short groundflash (~8 frames) is good for any explosion that gives off light. You can also use a longer groundflash to suggest the ground is glowing from heat.

Properties

CSmokeProjectile2

( newly added to wiki. someone cross-check then remove this note )

Particles that begin with a hard-coded yellow-red colorfade and then fade to monochrom. (shades of grey)

Movement is influenced by the random wind. Finer details of visual and position update are best explained by looking at the formulas in CSmokeProjectile2::Update() & CSmokeProjectile2::Draw()

Suggested Use

Smoke. Smokestacks, rocket exhaust, burning wreckage,...

For a nicer stream of smoke spawn it frequently over multiple frames, otherwise it looks rather bland.

Properties

CSmokeProjectile

Monochrome particles that fade out. A more "primitive" version of CSmokeProjectile2. No hardcoded red-yellow start but it misses wantedPos to tweak the look a bit more detailed.

Suggested Use

Smoke. For a nicer stream of smoke spawn it frequently over multiple frames, otherwise it looks rather bland.

Properties

Examples

'Balanced Annihilation' CEGs (TDF format)

'Conflict Terra' CEGs

'Evolution RTS' CEGs

'Imperial Winter' CEGs (TDF format)

'Journeywar' CEGs

'MechCommander: Legacy' CEGs (TDF format)

'Spring: 1944' CEGs (TDF format)

'Spring Tutorial Game' CEGs

'XTA' CEGs (TDF format)

'ZeroK' CEGs

Category:CEG