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connecting an object to a path in null

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andrej Setina
connecting an object to a path in null
on Sep 13, 2016 at 10:08:19 am

I have created a masking path in a tracked null and I would like that an object is following that path. How can I do that? Please help.
(I have a moving footage /map/ which is tracked and I want that a bus /object/ is moving along the path which I have created in null.


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Roei Tzoref
Re: connecting an object to a path in null
on Sep 13, 2016 at 9:44:54 pm

[andrej Setina] "I have created a masking path in a tracked null"

making masks on a null does not make too much sense. nulls are more for manipulating other layers for better control specifically for transform operations, not for masks since they do not render. the proper workflow for what you are looking for is probably to set a mask on a solid, then parent that solid to the null. now you have a mask following a null and this mask can be your track matte for any layer.


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andrej Setina
Re: connecting an object to a path in null
on Sep 14, 2016 at 7:53:09 am

Sorry, doesn't work at all.
Let me explain once more.

I have made a footage of a map (map is moving) - and tracked it
with a pen tool I have made a path (tried in "null", tried in "shape" and tried in "track solid")

I also have an object (vector of a car)

I would like that this vector car object is following the path on a moving map

sorry to say, I have spent 3 days and seems that I am a plain stupid :(


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Roei Tzoref
Re: connecting an object to a path in null
on Sep 14, 2016 at 8:25:30 am

it's o.k we will figure it out don't worry :)

we still need to figure out some things:

[andrej Setina] "I have made a footage of a map (map is moving) - and tracked it"
when you say "made a footage". do you mean you filmed a map on video with a real camera and imported that video file to After effects?


[andrej Setina] "I would like that this vector car object is following the path on a moving map
"


if you want an object to follow a path you do this:
1. draw the path on a solid layer (you might want to reduce it's opacity to see the actual path it's supposed to be on)
2. copy the path: make sure you copy the mask path, not the mask
3. paste the path on the position keyframe of the vector object
4. set the object to orient along path (layer->transform->auto orient)

a screenshot would be helpful too. you can copy you screenshot to the clipboard and paste it here


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andrej Setina
Re: connecting an object to a path in null
on Sep 14, 2016 at 9:40:39 am

1 - done
2, 3 - done - got a much smaller path and the object is moving from back to front








f you want an object to follow a path you do this:
1. draw the path on a solid layer (you might want to reduce it's opacity to see the actual path it's supposed to be on)
2. copy the path: make sure you copy the mask path, not the mask
3. paste the path on the position keyframe of the vector object
4. set the object to orient along path (layer->transform->auto orient)


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Roei Tzoref
Re: connecting an object to a path in null
on Sep 14, 2016 at 7:07:45 pm
Last Edited By Roei Tzoref on Sep 14, 2016 at 7:12:37 pm

the recipe I gave you is for 2d movement. when in 3d it could be more complicated. there is additional complexity as you are trying to track in 3D what is a google map video. this could go wrong in so many ways because this not a real video but computer generated satellite imagery. I cannot be sure what is wrong before seeing the video itself. you can upload an H.264 version of this video and I could suggest a decent workflow for this. I work with google maps all the time: video and stills. many times you could be better off not making a video with google but making a large still and it would simplify things. let's first see what goes on in this video.


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andrej Setina
Re: connecting an object to a path in null
on Sep 15, 2016 at 8:21:18 am

I just want that the bus is following the road.


10561_aesample.mts.zip


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Kalleheikki Kannisto
Re: connecting an object to a path in null
on Sep 15, 2016 at 8:45:54 am
Last Edited By Kalleheikki Kannisto on Sep 15, 2016 at 8:48:12 am

I would suggest a slightly different approach to simplify matters:

I would precompose the bus animation into the same layer (precomp), in 2D, the map being a large still image. The bus will be in the same perspective as the plane, but the task will be greatly simplified with little compromise. If you want the bus to keep approximately the same size regardless of camera move, it would need an expression that took into account the distance of the plane the 3D camera. For sake of simplicity probably the center point of the plane.

This way the 2D method for the motion path as described will work properly.

1/10th the trouble, with pretty much the same result.

Kalleheikki Kannisto
Senior Graphic Designer


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andrej Setina
Re: connecting an object to a path in null
on Sep 15, 2016 at 8:54:40 am

No problem if bus is always the same size.
Please be so kind and tell me what to do - I just have tons of same type animation and I am totally stuck.


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Roei Tzoref
Re: connecting an object to a path in null
on Sep 15, 2016 at 10:13:49 am
Last Edited By Roei Tzoref on Sep 15, 2016 at 10:20:20 am

I see. same as Kalleheikki Kannisto smart advice to you, I would not use video for this, but export a jpg and make this movement in after effects. this requires compositing sometimes. the simple approach would be this:
1. download your high resolution map from google maps (about 4k is the maximum I believe)
2. import to Ae and place inside an HD composition
3. precomp the footage layer - leave all attributes - now you have your precomp at the size of your footage. make the path animation there.
4. in the master comp make the movement
5. you could scale your bus to match the zooming out so it will be large even if you zoom out. you do this by matching the keyframes. there is more complicate approach for doing this via expressions.

I usually make this kind of composite in Ae's 3D which gives me more flexibility. I can also set my bus in 2D attached to a 3D null via toComp expression , and it will always be in the same size even if I zoom out, but this method is more complicated to explain or understand.

Here's a thread showing advice on how to composite and create movement on even bigger maps. one of the GIF's presented shows a similar path of a boat on a large scale animation. here it is:

https://forums.adobe.com/message/8988783#8988783


** this message was created using the NEW drag and drop feature in creative cow :). CreativeCow now supports copy pasting to the text field from your clipboard, and drag and drop. this feature is still in development but great news right???


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Kalleheikki Kannisto
Re: connecting an object to a path in null
on Sep 14, 2016 at 7:14:46 am
Last Edited By Kalleheikki Kannisto on Sep 14, 2016 at 7:18:11 am

To make a null follow a path, you copy the path to the position property of the null. However, you will already have position information keyframes on the null since you have tracked it to the footage. The solution is to create another null, paste the path there and parent the new null to the original one. If the nulls are 2D nulls, this will work. If you have 3D tracked the footage and created a 3D null, I doubt it will.

Pasting the path will create a 2-second animation, you can stretch it by dragging the last keyframe. See here:





Kalleheikki Kannisto
Senior Graphic Designer


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