Effect timelines

A .effect resource schedules presentation. Its length is not the duration of the gameplay status that requested it. A six-second status can keep a short visual loop active, then let an outro play when the loop breaks.

Use the custom-effects toolchain and begin with one particle track before building an animated sequence.

Read the timeline resource

Observed in vanilla: inspect base\fx\player\p_hacking_glitch\p_hacking_glitch_low.effect in WolvenKit. The root type is worldEffect.

Do not create unrelated copies of an event in the track and root event list. They must reference the same object. Keep CR2W handles separate from the event’s unsigned ruid.

Separate the three clocks

For a short animated effect, this is a useful starting layout:

timeline seconds: 0        0.2                     1.0          1.6
                 | intro  |  repeating motion      |  outro     |
                          +-----------------------+
                          loop range

status active -> presentation repeats the loop
normal stop   -> break loop -> finite outro -> finished

The intro is outside the loop. The outro and any one-shot exit sound are also outside it. Setting worldEffect.length to six seconds would instead change the presentation layout; it would not configure a six-second gameplay status.

Author one particle track in WolvenKit

1. Create or open a mod-owned .effect with a worldEffect root and PC cooking target. Inspect the reference’s group, track, and event types.
2. Add an effectTrack beneath the root group. Add a handled effectTrackItemParticles to its items array.
3. Set particleSystem to the exact archived .particle depot path.
4. Set timeBegin and timeDuration. These timeline values use seconds; do not copy millisecond values from a scene dialog event.
5. Give the item a unique ruid. Add the matching object reference to the root events array rather than constructing another item with the same ID.
6. Inspect alpha, emissionScale, size, and velocity. The constant-value setup uses effectEffectParameterEvaluatorFloat with a CEvaluatorFloatConst evaluator of 1.0 for each. A zero alpha or emission scale can hide otherwise valid particles.
7. Set the root length to cover the item, save, and reopen it. Check the track, item reference, particle path, evaluators, and RUID.
8. Bind the event to a placement in the entity descriptor.

For the first game check, use a single visible track and verify removal. A timeline item ending does not establish that an incompatible long-lived particle disappears with it.

Add the loop and outro

1. Put intro tracks before 0.2 seconds.
2. Add a loop marker beginning at 0.2, lasting 0.8 seconds.
3. Set the corresponding effectLoopData.startTime to 0.2 and endTime to 1.0. Keep the marker and loop table consistent.
4. Place the motion tracks entirely within that interval.
5. Put finite outro tracks at or after 1.0. Set the root length to the latest outro event’s end.
6. Test normal expiry, early removal, and reapplication. Normal loop break and an immediate effect stop can produce different cleanup behavior.

Loop-break, immediate-stop, and overlapping reapplication behavior are Experimental for a new effect. Design the gameplay owner to use the intended stop route, then test that route explicitly.

Animate images with tracks

Motion can be drawn into a sequence of original texture frames. Each frame has a particle resource, and the effect timeline selects them in order. This is texture animation; scattered pixels drawn into successive frames are not independent physics particles.

For eight motion frames over 0.8 seconds:

The intro can occupy 0.0–0.2. Twelve outro frames at 0.05 seconds each occupy 1.0–1.6, so the root length is 1.6.

Prepare the compiled particle lifetime for each interval. Timing a 0.1-second track does not rewrite a particle’s baked lifetime. Check for gaps, overlapping old frames, and a visible jump at the last-to-first loop boundary.

For separate opaque and glowing layers, give each layer its own particle track at the same frame times. Use separate material instances; a shared material cannot give each layer independent blend settings.

Put a one-shot sound after the loop

Add an effectTrackItemSound after the loop end. Set its eventName to an available game audio event, and keep its positionName consistent with the effect’s placement setup. ui_fx_hacking_glitch_fullscreen_low is an example of an existing electronic event name; it is not a WEM depot path.

For a loop ending at 1.0, a sound beginning at 1.005 stays outside the repeating interval. Give the sound its own RUID and compiled placement row. Listen in game: a valid event name alone does not establish audibility, spatialization, or one-time playback. Audio behavior here is Experimental.

Next: Entity spawners and status effects.