PDA

View Full Version : Blocking/shielding against fields

Henrik Hörlin
03-17-2003, 05:51 PM
Howdy all!

I'm doing a hovercraft/spinner type of craft that is supposed to take off using jets. Dust swirls and things are supposed to be affected by the (jet) thrusters.
When using a fan-field on a rigid body (softdrink can) standing on a passive rigid body (oil barrel) the can is blown off the barrel and drops to the floor. Here is where my problem starts:
When the can hits the ground it shuld not be affected by the fan, since the barrel is in the way. But the can is still blown away bay the fan. Is there any practical/easy way of setting up some sort of shielding?
I've thought about adding a dragfield on some of the barrels CVs facing away from the fan to compensate but if the fan moves I must adjust the strength of the drag-field... And since everythingis calculated exponentially... do the math. (I'd rather not). :)
Another way would be keying the intensety of the fan...
Yet another way would be using the volume shape of a cone...
Both of these have to many restrictions/workaraounds...
Any other sugestions... or am I just lazy?
alexx
03-17-2003, 08:30 PM
yes:
you are just lazy :)
Henrik Hörlin
03-18-2003, 11:48 AM
Damn!
I thought so... shuldn't hope too much I guess...

Back to figuring it out..:wip:
:rolleyes:
kag122
03-19-2003, 01:09 AM
You dont need to figure anything out, its all been explained :)

it would be just as easy to hook up seperate fields in the dynamic relationships editor.
Eg create a seperate field for the can.
Jozvex
03-19-2003, 05:46 AM
Yeah, what kag122 said.

Or you could convert the can's dynamics to keyframes, then just delete the keys after it falls off the barrel.
Henrik Hörlin
03-20-2003, 08:58 AM
Thanks for the replies/sugestions.

Silly me have found at least two new ways to do this since I last posted. One of them was what kag122 said, with a separate field for the cans. The other was to key the rigidbody interaction with the field when it has fallen below a value in Y.
But this last thing was more complicated that I thought and havn't really figured out how to make it work. But I'll get there.

Jozvex.
Do you mean the use of active/passive keys? Because if I convert the cans motion to keyframes that will include the fall to the ground (gravety field) as well. If I delete the keyframes after the can falls of the barrel, it will just hang there in the air? Can you explain a bit more?

The first post was posted very late... this post was posted quite early... I could be missing something here but hey... the number of posts in dynamics is quite low...:rolleyes: :hmm:
Thanks again.
alexx
03-20-2003, 06:37 PM
i think he means baking the dynamics to keyframes (edit->keys->bake simulation i think)
there you can have the dynamic simulation converted to keyframes.
then you can manually delete frames you dont need anymore and your animation will run like a breeze since the calculation has not to be done anymore (dont forget to disconnect your object from the rigid body)

cheers

alexx
Jozvex
03-20-2003, 10:43 PM
Yes, alexx is right about what I meant!
CGTalk Moderation
01-14-2006, 04:00 PM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.