Advice on sand and conditional judgment

[cgdvs]

When I was testing the sand, I suddenly thought of a problem. Add an "absolutely static" force to those that swell and move slightly. However, these sand speeds are "absolutely static" when they are less than a certain value. However, now I have added "SLOW" to achieve "absolute rest". Is there any way to achieve this idea? Of course, these “absolutely static” sands still have to collide with other sands in the scene.
Or I want to have a node that satisfies a certain condition and makes the particle "absolutely static" as if it were frozen.
There is another problem. In this scenario, I want the event_001 sand to output particles to the new event when it collides with event_002 (static sand). In other words, I want to detect the collision operation nodes of different sets of sand.
Another situation! I need to meet two or three conditions to output to a new event. For example, if the speed is less than 1 and event_001 collides with event_002, both conditions are satisfied and output to the next event.

If you have an "AND" node, you can receive multiple conditions and judgments at the same time. I think this problem will be solved.

When sand and sand pass each other "influence force", it is attenuated. After a few passes, the force disappeared completely.

[tyFlow]

I'm not sure what you mean by 'absolutely static'...you mean not moving but still colliding with other particles?

As for logical AND operators in property tests....soon all operators will get particle filters with AND/OR operators to control activation.

[cgdvs]

This operator is to make the particle physics particles stand still. This static means that when the particle velocity is less than 0.01, the position will not change. Even if a large number of object particles apply thrust to it, they remain in place. It will not be activated until it has a greater thrust.
I mean to prevent the sliding phenomenon in the particle physics, or the expansion problem.