Hello !
I just wanted to make sure that there was no problem with using multiple particle attachment components on a single particle group. I am also not sure about how to set the particle group by script, how can I choose it by name for example ?
I have a ton of other questions, but I'll try and search a bit more in the docs before flooding the forum
I hope I made myself clear, english is not my first language.
Cheers,
Vincent
Hi Vincent,
Attaching the same particle group to multiple transforms doesn't make any sense. Just like it doesn't make sense to have a transform with multiple parents (in fact, this isn't possible in any transform hierarchy implementation that I know of). What's your use case for this?
The manual specifies that in case of multiple attachments for the same particle, the result is undefined:
http://obi.virtualmethodstudio.com/tutor...ments.html
Quote:Particles affected by more than one attachment will follow the attachment that was updated last. The update order for attachment is undefined.
Particle groups are stored in a plain generic List<>. So you can access by index just like you would any other list:
Code:
var particleGroup = rope.blueprint.groups[index];
If you want to access them by name, you have to perform a linear search:
Code:
public ObiParticleGroup GetGroupByName(string name)
{
foreach (var group in rope.blueprint.groups)
if (group.name == name)
return group;
return null;
}
(08-10-2020, 08:00 AM)josemendez Wrote: [ -> ]Hi Vincent,
Attaching the same particle group to multiple transforms doesn't make any sense. Just like it doesn't make sense to have a transform with multiple parents (in fact, this isn't possible in any transform hierarchy implementation that I know of). What's your use case for this?
The manual specifies that in case of multiple attachments for the same particle, the result is undefined:
http://obi.virtualmethodstudio.com/tutor...ments.html
Particle groups are stored in a plain generic List<>. So you can access by index just like you would any other list:
Code:
var particleGroup = rope.blueprint.groups[index];
If you want to access them by name, you have to perform a linear search:
Code:
public ObiParticleGroup GetGroupByName(string name)
{
foreach (var group in rope.blueprint.groups)
if (group.name == name)
return group;
return null;
}
Thanks a lot for the response Jose !
For my use case, I guess I was not clear enough, my bad. I made a video to make it more obvious.
https://www.youtube.com/watch?v=cNQflI6b5IQ
I have a rope, at the end of which is a "hook" (symbolised here by the sphere that the character picks up) . Now that hook is already a dynamic particle attachment for the rope. But then I would like to attach a crate at the end oh the rope, in such a way that I can then drag that box around.
What you see in the video is a solution I'm trying : moving the "hook" above th crate, and adding a hinge joint to the crate. But has you can see it's pretty violent and unstable... My question, I guess, was just what the best way to achieve this in an efficient way is.
Hope it is clearer and thanks again
Make sure you're not forcing the rope to stay inside a collider that is also set to
collide with the rope. This will cause a force feedback loop, because the rope is simultaneously trying to stay inside the collider (due to the attachment/joint) and outside of it (due to collisions), which is a situation that can't be solved and results in unstable coupling with the rigidbody. This -along with its implications and solution- is described in the manual. See the last bit of the pin constraints page (linked to from the dynamic attachments page):
http://obi.virtualmethodstudio.com/tutor...aints.html
The correct choice in this case is to use a hinge joint (or a configurable joint) to attach the crate to the hook. Just make sure that:
1.- No collisions between the crate/hook and the end of the rope take place, as I just described.
2.- Mass ratios are reasonably small (that is, don't have a 1000 kg crate attached to a 1 gram rope, or viceversa)
cheers!