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vector
05-15-2013, 01:22 AM
Hi

I have a character walking on a not planar ground so I can't attach a bird rate envelope using a gradient with a "y distance to object" to a fixed null.
Is it possible to manage the bird rate using the y distance to a surface or any other solution?

prometheus
05-15-2013, 07:17 AM
Hi

I have a character walking on a not planar ground so I can't attach a bird rate envelope using a gradient with a "y distance to object" to a fixed null.
Is it possible to manage the bird rate using the y distance to a surface or any other solution?

a littlel hard to understand what youre after, screenshots would help.

character and fixed null and not planar ground, you mean you have a deformed ground, and in such case..how is it deformed?

why not parent a ref obj to you character while it moves ...maybe use the sticky modifier etc.

I dont get the whole picture on what you try to do though.

vector
05-15-2013, 12:58 PM
You are right, but at this moment not pictures to share to explain it better and my poor English doesn't help :( ...

I have a horse walking over a deformed ground... I attached nulls to the horse hoofs using point info node. When they touch the ground they might emit particles... because I don't know how to get it, I just apply a envelope to them to emit those frames in which they are touching the ground... but it would be great that way: when the nulls touch the ground they emit particles. If the ground was planar (not deformed) using just a null as reference object would be enough but not the case.

By the way, in my previous post I said "envelope using a gradient" when I mean use a texture gradient. I can't edit it... sorry

JoePoe
05-15-2013, 01:39 PM
How about setting the null emitter birth rate to collision. Make your uneven ground the collision object.

(FX isn't really my thing, but....... seems like a viable option) :)

You might have to "save transformed" if you are deforming the ground procedurally in order to get the frozen geometry.

I'm sure, however, there is a very elegant nodal solution somehow....

edit: you could even get rid of the nulls and have the bottom of the hooves themselves be the emitters....

prometheus
05-15-2013, 02:09 PM
you could add collision object instead of nulls and parent that to the horse hoof, or simply add the collision object to the nulls in the nulls properties/fx tab.
by using collision objects you can set the mode to event...and then also set the ground surface to emitt particles based on collision event.
you are trying to emitt the wrong way I think.

I might be able to post a scene sample with simple dummy objects to show the setup, not sure if I can set it up today..maybe tomorrow.

Michael

JoePoe
05-15-2013, 06:27 PM
Well, my sparks might not be the greatest, but.....
'Hoof"/null is emitter & ground plane is collision.

I tried switching the two and LW gave me the finger :bangwall:. (Probably has more to do with my crappy computer than anything else. I just haven't been able to test the alternative).

two questions though:
1) If the ground plane is the emitter won't all of the ground emit particles on event? Oh, maybe a gradient on Birth Rate with Distance to Object > Null as input!
2) Won't you need the ground plane (or a proxy of the ground plane) to be a collision object in order for the sparks to have someplace to land?


http://www.youtube.com/watch?v=N7EN7mkCZF0

prometheus
05-16-2013, 03:52 AM
[QUOTE=JoePoe;1322125]Well, my sparks might not be the greatest, but.....
'Hoof"/null is emitter & ground plane is collision.

I tried switching the two and LW gave me the finger :bangwall:. (Probably has more to do with my crappy computer than anything else. I just haven't been able to test the alternative).

two questions though:
1) If the ground plane is the emitter won't all of the ground emit particles on event? Oh, maybe a gradient on Birth Rate with Distance to Object > Null as input!

2) Won't you need the ground plane (or a proxy of the ground plane) to be a collision object in order for the sparks to have someplace to land?



1) No...the ground will only emitt particles based on the radius set in the collision event object, I would suggest having a lot of particles and some vibrations.

2) well..sort of true, you could use a proxy object, but how often do you see dust piling up on the ground, dust is best looking to dissapate so in the end you could probably get away with that..and let particles fall trough actually...I think it would look as it should anyway...keep the hypervoxels thin.

You also could manually set hoof emitter to start emitting on keyfames if you set the emitter key effect to key..if the animation isnīt to long.

I should add, when using collision event on A deformed/displaced terrain you need to calculate the particles.