Freeze Perticles revisited - a possible simple solution

[skinnytorus]

Hi, devs.

Since there's no particle caching ready at the moment, one possible solution to freeze particle movement when timeline might be a simple (imo this should be simple in code) hardcoded link between the Timeline controls and the particle simulation speed parameter.

The logic is this: Once Timeline receives STOP command from the Transport Controls, all particle layers in the scene set their Simulation speed to 0. Once Timeline receives PLAY command from the Transport Controls, Simulation speed in all particle layers gets restored. What do you think?

P.S. Such link may be optional and set in Preferences or in Particle Layer parameters. IMO the default state of such link should be ON.

[skinnytorus]

P.P.S This link might require to create an extra variable (a dynamic array?) to hold user simulation time float vars for all particle layers in the scene at a given time (basically, it's the current time the playhead is at). Particle systems must read this array var to know their sim speed. If Timeline is stopped, and the user makes edits to the Simulation speed field in the Particle layer Parameter page, then elements of this array should be dynamically updated. The idea is to make sure the user doesn't see zeros in all Simulation Speed parameter fields once Timeline is stopped.

Edit:
Or perhaps an even better idea might be not to update Simulation Speed parameter field exposed to the user at all, and perform all the read-write operations under the hood.