Emit smoke in object's local direction?

[cwalrus]

Hi - 

 

(I feel like this has a simple answer and i am having trouble figuring it out.) 

I just want smoke to come out of a torus, let's say along it's local Z axis. And then when I animate the torus, the smoke will continue to be emitted in that direction, changing along with the rotation of the torus.

 

I can get the smoke to emit only in velocity of Z, but I believe that's in world space and doesn't care about the local rotation of the torus.

 

Anyone know how?

 

thanks!

 

 

[iamyog]

Something like this ?

 

 

torus_rot_emission.hipnc

[3iart]

You're leaving out a fir bit of information. It's usually easier to understand a problem with a hip file.

 

How are you animating the torus? In Houdini? Alembic Cache?

 

If it's in Houdini, just assign your velocities before your transform and it should update properly.

 

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Edited February 3, 2016 by 3iart

[cwalrus]

Exactly like that Anthony!  thank you.

[cwalrus]

Hey there - one issue. The transforms I am required to follow are baked on the geo level - How do I get them inside my obj - onto the transform there? See attached file - it will make sense what I"m trying to do:

 

Think of an exhaust pipe behind a car...

 

Thanks!

 

cameron

[iamyog]

Split your sim into 2 nodes

set the emission direction inside the first one, it will inherit transformation from /obj level.

Then you object merge it into a second geometry node by making sure you set the Transform parameter to "Into this object"

 

 

torus_rot_emission2.hipnc

[cwalrus]

Once again, thanks so much!