My First Effect

In this tutorial you will learn how to create particle effects (Particle Effects, PFX) — from simple smoke, through fire, to rain and snow.

How Do Particle Effects Work?

The PFX system in Gothic emits particles (small textured sprites) from an emitter with a defined shape. Each particle has its own direction, speed, lifespan, and appearance.

Effects are defined as instances of the C_ParticleFX class in files in the System/PFX/ directory:

File	Description
PfxInst.d	General effects (fire, smoke, sparks, water, weather)
PfxInstEngine.d	Engine-required effects (blood, dust, water splash)
PfxInstMagic.d	Magic effects (spells, runes, auras)

The C_ParticleFX Class — Overview

The class has 49 fields divided into 7 categories. You don't need to set them all — fields you don't set will use default values (usually 0 or empty string).

1. Emission Rate — How Many Particles and When

Field	Type	Description
ppsValue	float	Base particles emitted per second
ppsScaleKeys_S	string	Time-varying multipliers, e.g., "1 2 3"
ppsIsLooping	int	1 = looping, 0 = one-shot
ppsIsSmooth	int	1 = smooth interpolation between keys
ppsFPS	float	Key playback speed (frames/sec)
ppsCreateEm_S	string	Child effect name (spawned per particle)
ppsCreateEmDelay	float	Child effect delay

2. Emitter Shape — Where Particles Come From

Field	Type	Description
shpType_S	string	Shape: "POINT", "LINE", "BOX", "CIRCLE", "SPHERE", "MESH"
shpFOR_S	string	Frame of reference: "OBJECT" or "WORLD"
shpOffsetVec_S	string	Offset: "X Y Z"
shpDistribType_S	string	Distribution: "RAND", "UNIFORM", "WALK", "DIR"
shpIsVolume	int	1 = emit from volume, 0 = from surface only
shpDim_S	string	Dimensions (shape-dependent)
shpMesh_S	string	Emitter mesh (when shpType_S = "MESH")
shpMeshRender_B	int	1 = render the emitter mesh

3. Direction and Speed

Field	Type	Description
dirMode_S	string	Mode: "DIR", "TARGET", "MESH_POLY", "RAND", "NONE"
dirFOR_S	string	Direction frame of reference
dirAngleHead	float	Horizontal rotation angle (°)
dirAngleHeadVar	float	Angle variance (±°)
dirAngleElev	float	Elevation angle (°); 90 = up, -90 = down
dirAngleElevVar	float	Elevation variance (±°)
velAvg	float	Average initial velocity
velVar	float	Velocity variance (±)

4. Particle Lifespan

Field	Type	Description
lspPartAvg	float	Average lifespan (ms)
lspPartVar	float	Lifespan variance (±ms)

5. Flight Behavior

Field	Type	Description
flyGravity_S	string	Gravity vector: "X Y Z"
flyCollDet_B	int	0 = no collision, 1 = collisions, 3 = collisions + marks

6. Visualization

Field	Type	Description
visName_S	string	Texture (.TGA) or model (.3DS)
visOrientation_S	string	Billboard: "NONE", "VELO", "VELO3D", "VOB"
visTexIsQuadPoly	int	0 = triangle, 1 = quad mesh
visTexAniFPS	float	Texture animation FPS
visTexAniIsLooping	int	0 = once, 1 = loop, 2 = ping-pong
visTexColorStart_S	string	Start color: "R G B" (0–255)
visTexColorEnd_S	string	End color (interpolated over lifespan)
visSizeStart_S	string	Start size: "W H"
visSizeEndScale	float	End size multiplier
visAlphaFunc_S	string	Blending: "BLEND", "ADD", "MUL"
visAlphaStart	float	Start alpha (0–255)
visAlphaEnd	float	End alpha (0–255)

7. Additional Effects

Field	Type	Description
trlFadeSpeed	float	Trail fade speed
trlTexture_S	string	Trail texture
trlWidth	float	Trail width
mrkFadeSpeed	float	Mark (decal) fade speed
mrkTexture_S	string	Mark texture
mrkSize	float	Mark size
flockMode	string	Flocking mode: "WIND"
flockStrength	float	Flocking strength
useEmittersFOR	int	1 = particles follow emitter position
timeStartEnd_S	string	Render time window: "8 22" (8am–10pm)
m_bIsAmbientPFX	int	1 = ambient effect (can be disabled in gothic.ini)

---

Example 1: Simple Smoke

Let's start with something simple — a column of smoke rising upward:

instance PFX_MySmoke (C_ParticleFX)
{
    // --- Emission: 30 particles/sec, continuous ---
    ppsValue        = 30;
    ppsScaleKeys_S  = "1";
    ppsIsLooping    = 1;

    // --- Shape: point ---
    shpType_S       = "POINT";
    shpFOR_S        = "OBJECT";

    // --- Direction: upward with random variance ---
    dirMode_S       = "DIR";
    dirFOR_S        = "OBJECT";
    dirAngleElev    = 90;               // upward
    dirAngleElevVar = 15;               // ±15° variance
    dirAngleHeadVar = 180;              // spread sideways
    velAvg          = 0.02;             // slow
    velVar          = 0.01;

    // --- Lifespan: 2–3 seconds ---
    lspPartAvg      = 2500;
    lspPartVar      = 500;

    // --- No gravity (smoke rises) ---
    flyGravity_S    = "0 0.0001 0";     // slightly upward

    // --- Appearance ---
    visName_S           = "SMOKE1.TGA";
    visOrientation_S    = "NONE";           // billboard facing camera
    visTexColorStart_S  = "150 150 150";    // gray
    visTexColorEnd_S    = "80 80 80";       // darkens over time
    visSizeStart_S      = "10 10";
    visSizeEndScale     = 5;                // grows 5x
    visAlphaFunc_S      = "BLEND";          // standard blending
    visAlphaStart       = 180;
    visAlphaEnd         = 0;                // fades out
};

tip

visAlphaFunc_S — blending modes:

• "BLEND" — classic blending (smoke, fog, dust)
• "ADD" — additive (fire, sparks, magic — bright, glowing)
• "MUL" — multiplicative (shadows, darkening)

Example 2: Campfire

Fire combines fast emission, additive blending, and animated textures:

instance PFX_MyFire (C_ParticleFX)
{
    // --- Emission: lots of particles, continuous ---
    ppsValue        = 80;
    ppsScaleKeys_S  = "1";
    ppsIsLooping    = 1;

    // --- Shape: circle (fire base) ---
    shpType_S       = "CIRCLE";
    shpFOR_S        = "OBJECT";
    shpIsVolume     = 1;
    shpDim_S        = "15";             // radius 15 units

    // --- Direction: upward ---
    dirMode_S       = "DIR";
    dirFOR_S        = "OBJECT";
    dirAngleElev    = 90;
    dirAngleElevVar = 20;
    dirAngleHeadVar = 180;
    velAvg          = 0.05;
    velVar          = 0.02;

    // --- Lifespan: short (fast fire) ---
    lspPartAvg      = 800;
    lspPartVar      = 200;

    // --- Slight upward gravity (hot air) ---
    flyGravity_S    = "0 0.0003 0";

    // --- Appearance ---
    visName_S           = "FIREFLARE.TGA";
    visOrientation_S    = "NONE";
    visTexAniFPS        = 8;                // texture animation
    visTexAniIsLooping  = 1;                // looped
    visTexColorStart_S  = "255 255 255";    // white (overexposed center)
    visTexColorEnd_S    = "255 100 30";     // orange (edges)
    visSizeStart_S      = "5 5";
    visSizeEndScale     = 4;                // grows
    visAlphaFunc_S      = "ADD";            // additive = glowing
    visAlphaStart       = 255;
    visAlphaEnd         = 0;
};

Example 3: Sparks

Sparks are small, fast particles with gravity and collisions:

instance PFX_MySparks (C_ParticleFX)
{
    // --- Emission: one-time burst ---
    ppsValue        = 50;
    ppsScaleKeys_S  = "1 0";           // instant burst, then nothing
    ppsIsLooping    = 0;                // one-shot
    ppsFPS          = 2;

    // --- Shape: point ---
    shpType_S       = "POINT";
    shpFOR_S        = "OBJECT";

    // --- Direction: scatter in all directions ---
    dirMode_S       = "DIR";
    dirFOR_S        = "OBJECT";
    dirAngleHeadVar = 180;              // full 360°
    dirAngleElev    = 45;               // slightly upward
    dirAngleElevVar = 45;               // but with wide variance
    velAvg          = 0.15;             // fast
    velVar          = 0.08;

    // --- Lifespan: short ---
    lspPartAvg      = 600;
    lspPartVar      = 300;

    // --- Gravity pulls down ---
    flyGravity_S    = "0 -0.0005 0";
    flyCollDet_B    = 1;                // collision with world

    // --- Appearance: small, bright dots ---
    visName_S           = "ZFLARE1.TGA";
    visOrientation_S    = "NONE";
    visTexColorStart_S  = "255 220 100";    // yellow
    visTexColorEnd_S    = "255 80 20";      // dark orange
    visSizeStart_S      = "2 2";
    visSizeEndScale     = 0.5;              // shrink
    visAlphaFunc_S      = "ADD";
    visAlphaStart       = 255;
    visAlphaEnd         = 0;
};

Example 4: Snow

Snow uses a large emitter high above, with slowly falling particles:

instance PFX_MySnow (C_ParticleFX)
{
    // --- Emission: continuous ---
    ppsValue        = 50;
    ppsScaleKeys_S  = "1";
    ppsIsLooping    = 1;

    // --- Shape: large circle high above the player ---
    shpType_S       = "CIRCLE";
    shpFOR_S        = "OBJECT";
    shpOffsetVec_S  = "0 500 0";        // 500 units above emitter
    shpIsVolume     = 1;
    shpDim_S        = "300";            // radius 300

    // --- Direction: downward ---
    dirMode_S       = "DIR";
    dirFOR_S        = "OBJECT";
    dirAngleHead    = 20;               // slight wind
    dirAngleHeadVar = 10;
    dirAngleElev    = -89;              // nearly straight down
    velAvg          = 0.05;
    velVar          = 0.02;

    // --- Lifespan: long ---
    lspPartAvg      = 5000;

    // --- No gravity (constant fall speed) ---
    flyGravity_S    = "0 0 0";

    // --- Appearance: white flakes ---
    visName_S           = "MFX_SLEEP_STAR.TGA";
    visOrientation_S    = "NONE";
    visTexColorStart_S  = "255 255 255";
    visTexColorEnd_S    = "255 255 255";
    visSizeStart_S      = "5 5";
    visSizeEndScale     = 1;
    visAlphaFunc_S      = "ADD";
    visAlphaStart       = 255;
    visAlphaEnd         = 255;

    // --- Ambient effect (can be disabled in options) ---
    m_bIsAmbientPFX     = 1;
};

Example 5: Blood (Child Emitters)

The child emitter system lets you create complex effects. Blood in Gothic consists of two instances — the main one (blood spray) and the child one (ground splat):

// Main effect: blood spray scattering
instance PFX_MyBlood (C_ParticleFX)
{
    ppsValue            = 64;
    ppsCreateEm_S       = "PFX_MyBlood_Splat";     // child effect!

    dirMode_S           = "DIR";
    dirFOR_S            = "OBJECT";
    dirAngleHeadVar     = 30;
    dirAngleElevVar     = 30;
    velAvg              = 0.1;
    velVar              = 0.05;

    lspPartAvg          = 750;
    lspPartVar          = 550;

    flyGravity_S        = "0 -0.0001 0"; // falls
    flyCollDet_B        = 1;

    visName_S           = "BLOOD1.TGA";
    visTexColorStart_S  = "255 255 255";
    visTexColorEnd_S    = "255 255 255";
    visSizeStart_S      = "6 6";
    visSizeEndScale     = 1;
    visAlphaFunc_S      = "BLEND";
    visAlphaStart       = 255;
};

// Child effect: ground splat
instance PFX_MyBlood_Splat (C_ParticleFX)
{
    ppsValue            = 1;
    ppsIsLooping        = 0;            // single splat

    shpType_S           = "POINT";

    dirMode_S           = "NONE";       // no movement
    velAvg              = 0;

    lspPartAvg          = 3000;         // 3 seconds

    visName_S           = "YOURBLOODSPLAT.TGA";
    visSizeStart_S      = "10 10";
    visSizeEndScale     = 1;
    visAlphaFunc_S      = "BLEND";
    visAlphaStart       = 200;
    visAlphaEnd         = 0;            // fades out
};

info

ppsCreateEm_S — each particle from the main emitter becomes a source for a new child effect. This is a powerful tool but expensive — use carefully to avoid overloading the engine.

Emitter Shapes

Shape	shpType_S	shpDim_S	Description
Point	"POINT"	—	Emission from a single point
Line	"LINE"	"100" (length)	Emission along a line
Box	"BOX"	"W H D"	Emission from a rectangular area
Circle	"CIRCLE"	"50" (radius)	Emission from a circle (or disk when shpIsVolume = 1)
Sphere	"SPHERE"	"50" (radius)	Emission from a sphere
Mesh	"MESH"	"250" (scale)	Emission from a 3D mesh surface

shpIsVolume

• shpIsVolume = 0 — particles appear on the edge of the shape (e.g., on the circle circumference)
• shpIsVolume = 1 — particles appear inside the shape (e.g., within the entire circle)

Particle Orientation

Mode	visOrientation_S	Description
Billboard	"NONE"	Particles always face the camera (default)
Along velocity	"VELO"	Particles stretched in movement direction (rain, sparks)
3D along velocity	"VELO3D"	Like VELO, but with full 3D rotation
Object	"VOB"	Orientation matches the parent object

Registration in ParticleFX.src

Particle effects have a separate compilation from game scripts. Add your file to System/ParticleFX.src:

_intern\ParticleFx.d
Pfx\PfxInstEngine.d
Pfx\PfxInst.d
Pfx\PfxInstMagic.d
Pfx\MyPfx.d

warning

PFX effects are not compiled by Gothic.src — they use their own ParticleFX.src file in the System/ directory.

Practical Tips

Performance

• Higher ppsValue means more particles = more computation
• flyCollDet_B with many particles heavily loads the CPU
• useEmittersFOR = 1 combined with flyCollDet_B is the most expensive combination
• ppsCreateEm_S multiplies the number of effects — each particle creates a new emitter

Debugging

• If the effect is not visible, check that visAlphaStart > 0 and visSizeStart_S is not too small
• Verify that the texture (.TGA) exists in the Textures/ directory
• Effects with m_bIsAmbientPFX = 1 can be disabled in game options

Common Patterns

Effect	Key Settings
Smoke	BLEND, large visSizeEndScale, visAlphaEnd = 0
Fire	ADD, animated texture, short lspPartAvg
Sparks	ADD, one-time burst, downward gravity, collisions
Rain/Snow	Large CIRCLE emitter, Y offset, dirAngleElev = -89
Blood	BLEND, gravity, child emitter (splats)
Magic/Aura	ADD, CIRCLE emitter, useEmittersFOR = 1

Summary

Creating particle effects requires:

1. An instance of the C_ParticleFX class with appropriate parameters
2. An emitter shape (shpType_S) — where particles come from
3. Direction and speed — how they move
4. Visualization — texture, color, size, blending
5. Registration in ParticleFX.src (not in Gothic.src!)