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EricChadwick
01-04-2008, 03:30 PM
I can't figure out how to get my arrow particles to look at the camera, but also orient in speed space. I'd like the arrows to be flat to the camera, but roll about their up axes so they always face the direction of travel.

Is this possible?

Pictures!
1. A mockup of my desired result.
2. Shape Facing operator gives me the lookat but kills the speed follow.
3. Speed follow doesn't give me the lookat.

JohnnyRandom
01-04-2008, 04:23 PM
Here you go, haven't tested with spawn op though.

EricChadwick
01-04-2008, 04:40 PM
Thanks for the example John. Unfortunately the Rotation op's Z value doesn't help when the camera moves. If I orbit around the particle I get all kinds of weirdness, especially when the deflector is at an angle. Hmm, need to play with this some more.

JohnnyRandom
01-04-2008, 05:22 PM
Ah never as simple as it seems :D It's not perfect but with a little tweaking I thinks you can get it to work.

I was messing around with it a little more. Moving the camera on the z-axis is a little strange, if you untick "use parallel direction" and switch to "orientation" center in the shape facing op, it yields ok results.

Not sure if you will be able to keep it perfectly facing the camera just because of the z-depth of the individual particles.

On a side note: you get a pretty cool effect with a "go to rotation" test in event 04.


Anyways I would be curious to know how, if you get it working like you want:)

best regards,
john

Here is an updated version.

EricChadwick
01-05-2008, 05:38 PM
Thanks again John! I do need this effect, I'll test out your example on Monday, let you know how it goes and what I find. It's NDA material but I might be able to sneak you a cleaned pic.

EricChadwick
01-07-2008, 03:06 PM
OK, so I have a couple questions about the setup.

1. Is Box1 required? I don't have it installed. The facing effect still seems to work OK, but Box1 is sitting there unconnected in Event03. Maybe the reason for question 3?

2. Why does Spawn01 have to use By Rate? Not a big deal, works fine as-is. I just can't figure out why By Travel doesn't work.

3. Why do the Facing particles seem to have their pivots on their left sides? Your instance shape has a left-side pivot, but PF doesn't have a Shape Instance operator. If I reset the pivot and add a Shape Instance below Shape Facing, it re-centers the particles, but then turning off the Shape Instance reverts them to the offset pivot. What's going on here?

Thanks for your help. This is great.

(edit... added a screenshot of your setup)

JohnnyRandom
01-07-2008, 03:23 PM
Hi Eric,

Event 3 only has a utility in it and is not necessary for the flow.

I Couldn't get it to work with travel by distance. It is odd.

The shape instance of the plane is merely for reference, so you can check the material, Initially I had a shape instance but it was doing some funky stuff so I took it out, I was playing with the pivot...

-John

EricChadwick
01-07-2008, 04:02 PM
Well the weird thing is that it's using Shape Facing but the pivot is not centered. Can't figure that out. Maybe just a ghost in thw machine, just need to re-do it from scratch.

JohnnyRandom
01-07-2008, 04:33 PM
You can adjust the shape facing Pivot to either top, bottom, or center in the ops params.

Reseting the pivot on the plane object with the arrow should not make any difference.

EricChadwick
01-07-2008, 06:23 PM
Ah, ok, got it to work. Thanks again.

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