Quote:I see, however you can create identical two force zones with different force values and then use collision filters so that one force zone affects rope A and the second force zone only affects rope B.Yes this is what I said in my init post. It may work for 2 ropes but does not work if rope number increases.
This is simple to setup, however you may run into scalability issues if you need many different zone/actor combinations.
Quote:Having an individual callback per particle would be way too costly in the CPU backend - with each call happening in a different thread, limiting usefulness - and outright impossible to do in the GPU backend.
Maybe force zone can support a callback per actor, and let us change data for different actors?
Quote:So you end up with fluidDensity/particleDensity = fluidMass/particleMass, volume does not appear. That's why I proposed particleMass = densityRatio as a solution.
I've tried set particleMass=0.001 and Force to 0.01, expecting to get 0 accelation but the behavior is a little different with accelation mode=9.8. May be related to the fact that my rope's mass is not totally same. The control point's mass is different as I want to keep a low mass ratio with the attachment. For now I'll go with accelation mode, use main rope's density to calculate accelation value, and use multiple force zone if there are more ropes need to appear at the same time (in my game, at most 3 force zones are needed so it should be ok with this approach) .
As a summary, rope bouyancy simulation cannot be easily done with force zone, given below condition
1. >1 ropes need to be in force zone at the same time. (use >1 force zones can help if there is only little ropes though)
2. Ropes have different density, and are non uniform quality ropes
It'd be better if force zone can expose a callback per actor to let us change current force zone settings per actor in future release.