Quick answer: Unreal Niagara mesh particle with animated UV offset wrapping at unexpected positions? UV value is fractional but read as int in fixed-point shader - use floating-point UV in particle attribute.
Trail particles with scrolling UV produce visible jumps every second instead of smooth flow.
Use float UV attribute
Particle attribute as Float, not Int. Continuous fractional values; shader interpolates smoothly.
Verify with the GPU debugger
RenderDoc capture. UV value per-vertex: continuous = correct, stepped = wrong attribute type.
Or compute in shader
Pass age; compute UV = age * scroll_speed in the material. Centralized; no per-attribute risk.
“Particle attributes are typed. Type errors are silent rounding bugs.”
Audit particle attribute types when adding scrolling effects. Float for continuous; Int for discrete; neither for both.