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Paste motion path to Z space

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Mikko KovasiipiPaste motion path to Z space
by on Sep 25, 2009 at 9:51:35 am

Hi. I'm trying to paste a path from illustrator to a Null object as an motion path and I would like it to be rotated 90° as it would be and move on the floor. Direct copy-paste makes it only move in x and y axis so it won't work. Then I tried to copy the path to a Solid layer, rotate it and then copy-paste it to the Null. It won't work either. Then I tried to make another Null, link the first to it and rotate it. Won't work. It just rotates the Null not the path. So how can I rotate the path? I'm trying to make a welding torch with Particle World that welds the floor. (attaching the particles to the null is not a problem)



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jordan cadbyRe: Paste motion path to Z space
by on Sep 25, 2009 at 4:28:48 pm

Hey Hey

havent tried this... but copy and paste to the object then link that to a null, appropriately rotate the null (90 degrees), then rotate the object back to you so its facing the camera again...

is that clear? hmm basically rotate an attached null to send the path off back in z space. or you could just past the motion path on to the null and attach an object (your layer) to it, but perpendicular... making a t shape

let me know if it pans out


in the shade

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Kevin CampRe: Paste motion path to Z space
by on Sep 25, 2009 at 8:15:18 pm

can you just leave the path/motion path on the xy plane, attach the emitter but then rotate the camera so that the xy plane appears to be the floor?

Kevin Camp
Senior Designer

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Mikko KovasiipiRe: Paste motion path to Z space
by on Sep 27, 2009 at 10:55:01 am

Thanks to both of you Jordan and Kevin. I tried that Jordans method but it didn't quite work either. If I have a motion path on an object and I parent it to null it somehow takes the Nulls coordinates and the motion path coordinates and moves it to start at the zero point at left top corner. Can't really explain this but something that it does.
The Kevins idea is quite good but I have all the other elements set up where I want them to be and if I move the camera I need to rotate and move all the other elements also. But I'm guessing that would go a lot faster than strugling with this..



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Mikko KovasiipiRe: Paste motion path to Z space
by on Sep 27, 2009 at 2:39:09 pm

Ok. Now I did move the camera and every other but I ran in to a problem with the gravity of the Particles. They are going to wrong direction. :(

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Kevin CampRe: Paste motion path to Z space
by on Sep 28, 2009 at 3:22:04 pm

if you are still using cc particle world, you can change the axis that gravity works on.

click 'options' at the top of the plugin settings, then click gravity. change the the y-axis value to 0.0 and the z-axis to 1.00 (or maybe -1.00).

another option would be to try and map the xy plane movement of the null to the xz plane of the particle producer...

so the producer's position x property would be and expression like this:
(thisComp.layer("Null 1").transform.position[0]-(width/2))/width

and the position z property like this:
-1*(thisComp.layer("Null 1").transform.position[1]-(width/2))/width

you can change the direction of the position z by removing the '-1*' at the front, but it seemed like -1 produced the right direction.

i'm sure this can be done with layer space transformations within the expression (using the method where the animated null is parented to another, then turned 90 degrees so it is on the xz plane), but those always take me longer to figure out (i just don't use them often enough). you may want to post in the ae expression forum... using layer space transformations would be the correct way to derive those values, but i think my manual hack of the values will work too.

Kevin Camp
Senior Designer

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Alejandro BenaventeRe: Paste motion path to Z space
by on Sep 23, 2013 at 2:26:26 pm

Ok, I know this thread is pretty old already, but I just stumbled upon this problem in my own project and haven't been able to find a solution on the net, despite it being quite a common issue.

This is the multi-step solution I found that works for me, which I'd like to share for the record. I've tested it on CS6, but I reckon it should work with previous versions as well.
(Just to clarify, people often find this problem because in a 3D oriented project, we usually start up by creating a new plane and rotating it 90º to serve as the world floor. Then we build everything on top of it, but further down the development process, if you try to paste a motion path into a layer's position property, the path will run on the x-y plane which, in your comp, will be right-left-up-down, rather than the floor's right-left-near-far which is probably what you intended. It's a little bit difficult to explain until you get stuck with it.)
So, on with the solution:

1. Create a new Null (1), make it a 3D layer.
2. Copy your mask/path/vector shape, paste it into your Null (1) position property (now, the null has the right motion path, but it travels on the wrong plane).
3. Create a new Null (2), make it 3D. Parent the first Null (1) to this Null (2). Rotate Null (2) 90º on the desired axis (probably x). (Now you have "knocked over" your Null (1) with its moving path onto the floor, and it is moving on the correct plane).
4. Delete Null (2). Null (1) is now moving on the correct plane (probably x-z) with no parent, but its axis are twisted (z pointing upwards).
5. Create new Null (3), make it 3D. Copy Null (2) position property, paste it into Null (3) (or paste it directly into your final moving object). Now, Null (3) (or your object) is moving on the floor plane along the desired path, and its axis are correctly aligned.

Hope this helps you out!

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