Particle Condition - Check if the particle is entering or leaving a 3D mask

The mask condition is based on a 3D Mask. This type of mask is in 3D, and has a value of 0% (where it masks nothing) and a value of 100% (where it masks fully). The values are interpolated from 0 to 100 in-between. The particle event will be triggered if the particle crosses a threshold (entering or going out of the mask).
As an example, if a threshold = 50% and the mask is a Linear mask, starting at (0, 0, 0) and ending at (0, 0, 10), the threshold will be crossed if a particle goes from (0, 0, 4.5) to (0, 0, 5.5). This is because the threshold is at 50% of the linear mask.
This can work with any kind of 3D Mask: you could check if a particle enters or leaves a sphere, a cube, a composite mask made out of many different 3D masks, etc., etc.


  • 3D Mask: Select the type of mask that should be used
  • Threshold that should be crossed to trigger the condition (entering or leaving)

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