Body Force

[musicnblood]

Hey. I'm trying to use the body force helper to create attraction but I'm not seeing any change in my liquid simulation. I have set the object and then tried playing with strength and max distance. I've tried different combinations of one high, one low, both high, both low but I never get any visible change in the movement of my liquid. The object is inside my phoenix grid. The body force is outside the grid. I've tried several different setups and distances between my liquid and my object. Can someone please explain the proper use of this helper and the correct settings to get attraction.

Also, can it repel?

Thank you for any knowledge you can share!

Chloie

[Ivaylo Katev]

can you attach the scene, without it can't say what is the problem

[musicnblood]

simple scene attached

Hey Ivaylo!

I've attached a simple scene like what I have been using to test out the settings on the body force helper. Thank you for taking a look!

Chloie

[Ivaylo Katev]

can you tell me a brief history of the scene? how is it created, did you load any presets and such things.
you did managed by some unclear way to switch to the old liquid core, this is the reason for the problem.
it's important for us to know how this happens, because other users also can hit the same problem, we have to prevent this if possible

[musicnblood]

This is just a simple scene I created just to upload to you. It isn't for anything but showing how I have tried to set up and use the body force. I have download the example wine scene and saved out the preset from the simulator and loaded that preset into the liquid simulator in my scene. I do this because when using my core to simulate, my liquid is un-renderable and cannot create a visible mesh. I have already been emailing chaos group support about this issue and they have provided me a script to put into max script listener in order to fix this problem but my company has already decided they don't want me wasting time creating liquid simulation settings when you have free set ups already working that I can download and save out in less time. But this is completely off topic.

So, I have created a new scene. I have not loaded any presets. The result is exactly the same with no attraction happening.

Perhaps my question is unclear. I'm just curios how the body force SHOULD work. As in: "is fade start the same as fall off and if so is the default 1 equal to 1cm? Does that mean that regardless of the body force strength, it will not reach simulated smoke, fire, or liquid that is more then 2 or 3 cm away?"

I was really just wondering about the generic set up of the body force that would give anyone an ideal how to us it in any scene. Such as "what does Suppress orb. mean?"

Perhaps there is a description page such as the very nice one that exist for the old attraction force that I'm just not finding.

[Ivaylo Katev]

ok, i see, the preset was causing the problem. the liquid simulator in the nightly builds uses a new flip based core, the old scenes are grid based and their settings are for the old core.
the invisible mesh problem was also related to similar issue, it's resolved now, but my advice is to not use the samples, if you are using a nightly build. we are preparing updated samples, and they will work with the flp as expected, the old ones are for the old core.
here is a short description of the body force parameters:
strength - it's obvious
max distance - limitation of the force by distance, the units are the scene units
fade start - parameter between 0 and 1 showing how "sharp" the force disappears when reaching the distance limit. 0 means the force decreases slowly and fully disappears reching the distance limit. 1 means the force is the same until the limit is reached, where it disappears rapidly. speaking technically, fade start is the part of the distance limit where the fade out of the force is started to be applied
suppress orb. - suppressing the orbital movement, this is a mechanism to "motivate" the liquid to fall over the body, otherwise it can stay in stable orbit like a satellite around the earth
internal damp - this parameter damps the liquid movement inside the body (if non solid), if zero the liquid will pass the body and will leave its volume from the opposite side. if 1 the liquid is stopped immediately when enters the body. the intermediate values just decrease the liquid movement making it to settle
damp min vel. - this parameter is related to the above mentioned damp of the liquid movement inside the body. in the most cases you need the liquid to not freeze totally, but to remain some movement showing that this is liquid, not ice. this parameter is a threshold for the damp mechanism, only the velocity above it is damped

[musicnblood]

Just to clarify, in the last scene I sent you, with NO preset used, I get NO reaction from the body force helper. I have not been able to get it to produce any visible results.

I found this https://vimeo.com/135438246 with downloadable file and was able to simulate his scene just fine. The body force helpers worked just like they do in his video.

The build I'm using is Build ID: 1510206357

It sounds like what I need to do to get my body force helper working is to download a different version of the nightly build. I am requesting access from support now.

Thank you for the description of the settings for the body force helper! I was able to play with the settings inside the scene I downloaded (Not my own scene!) The descriptions are helping me get the look I'm going for ten times faster then blindly setting up simulations and just getting a feel for each setting!

Thank you very much for your help Ivaylo!
Chloie