rk_spark
Spark and burning-debris streak. The card's Y axis lies along the particle's motion (`zero_billboard_streak`) and the graph stretches it by speed, so the fragment draws a thin line along the card, brightest at the head (+Y) and fading toward the tail, plus a bright spot at the he…
rk_spark
Spark and burning-debris streak. The card's Y axis lies along the particle's motion
(zero_billboard_streak) and the graph stretches it by speed, so the fragment draws a thin line
along the card, brightest at the head (+Y) and fading toward the tail, plus a bright spot at the
head. The colour is the lane colour times that shape, the lane opacity and gain, returned with
alpha 1 for additive blending.
The launch graph (launch/launch.procGraph) draws its sparkStreaks output with it (additive,
gain 1.4): sparks and burning chunks thrown from where the exhaust hits the ground, bouncing off
the scene, stretched from 1.5 to 9 times their size over speeds 0 to 30, and coloured from an HDR
ramp that cools from (12, 9, 4.5) to dark red over life. In the Procgen Effects Showcase world, the fx_launch scene plays the graph.
The shader includes @builtin::shaderModules.billboard.
Properties
| Property | Type | Default | Meaning |
|---|---|---|---|
gain | float | 1.0 | Multiplies the output colour (minimum 0). |
vertexBoundsDilation | float | 0.3 | How far the vertex hook moves a vertex past the mesh, in world units: the culling bounds grow by it so a moved vertex stays inside them. |
Lanes
| Lane | Carries |
|---|---|
data0.rgb | HDR colour. |
data0.a | Opacity, multiplied into the colour. |
Scoped to this part · feeds back into the world's score.