Quick answer: Construct 3 game stuttering when multiple effects stack on one object? Each effect requires a GPU readback - limit stacked effects or pre-bake the chain.
Boss VFX layers blur + bloom + chromatic. FPS halves the instant all three are active.
Limit effect stacking
Cap at 2 effects per object. Construct 3 chains them via render-to-texture; each link is a GPU pipeline flush.
Pre-bake the chain
For static effect combos, author a single shader effect that does all three operations in one pass. One fewer readback per object per frame.
Profile the GPU
Browser devtools > Performance > GPU. Long bars during gameplay are readback stalls. The fix verifies as shorter bars.
“Each effect is a render target. Render targets are expensive.”
For mobile web, treat effect count as a hard budget. Two per visible object, no exceptions, written on the wiki.