[HELP] Polar coordinate problem with transform

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[HELP] Polar coordinate problem with transform

Postby Gosh_Uhfa on 05/24/2015, 7:27 am

Hello, I`ve got a problem with the Sci-Fi weapon FX tutorial.
After I add "transform" effect to the footage, the circle created by polar coordinate (Rect to Polar) SPLIT!
There`s a rift on the circle and I cannot get rid of it.
Please help!
Thank you very much.
Attachments
123.png
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Re: [HELP] Polar coordinate problem with transform

Postby star+circle on 05/30/2015, 8:41 am

Probably just need to make sure the layers extends all the way across the image and that it hasn't been accidentally moved so one side is not all the way to the edge. Is your fire footage same or higher resolution as your comp?
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Re: [HELP] Polar coordinate problem with transform

Postby Gosh_Uhfa on 06/3/2015, 6:49 am

star+circle wrote:Probably just need to make sure the layers extends all the way across the image and that it hasn't been accidentally moved so one side is not all the way to the edge. Is your fire footage same or higher resolution as your comp?


Thx for the reply!!
My fire footage has the same resolution as my comp.
And I`m sure it hasn't been accidentally moved.
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Re: [HELP] Polar coordinate problem with transform

Postby star+circle on 06/4/2015, 9:38 am

Then I would check if the fire footage itself has a small black edge. I tested polar coordinates with some footage and it didn't leave a gap.

Perhaps enlarge the footage a smidgen and mask off the edge?
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Re: [HELP] Polar coordinate problem with transform

Postby Gosh_Uhfa on 06/4/2015, 9:12 pm

star+circle wrote:Then I would check if the fire footage itself has a small black edge. I tested polar coordinates with some footage and it didn't leave a gap.

Perhaps enlarge the footage a smidgen and mask off the edge?


For your information, the fire footage was completely circular when not add "Transform" effect.
However, when I add Transform effect on it to make it a inward circle, the gap shows up.
I am 100% sure it is the problem of transform effect but I don`t know how to fix it.
Attachments
fire.png
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Re: [HELP] Polar coordinate problem with transform

Postby star+circle on 06/5/2015, 9:56 am

Hi Gosh_Uhfa,

Ok, I see the problem now, adding a Transform before Polar Coordinates messes it up. Transform must be adding some extra pixels around the footage. Try putting a Motion Tile effect with Output Width of 99.8 (or some similar value) between the transform and Polar Coordinates. (Different size footage seems to need a different Motion Tile setting to fix the gap.)
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Re: [HELP] Polar coordinate problem with transform

Postby Gosh_Uhfa on 06/8/2015, 10:39 am

star+circle wrote:Hi Gosh_Uhfa,

Ok, I see the problem now, adding a Transform before Polar Coordinates messes it up. Transform must be adding some extra pixels around the footage. Try putting a Motion Tile effect with Output Width of 99.8 (or some similar value) between the transform and Polar Coordinates. (Different size footage seems to need a different Motion Tile setting to fix the gap.)

Thx for the reply again!!
Well your method did show me a concept to solve the problem, but I still can`t fix the problem.
1.I try your advice, add a Motion Tile effect with Ouput Width of 99.8 (or some similar value, I`ve adjusted that several time).
It only made the gap thinner but not filling it.

2. However, when I move the Motion Tile effect between the first Polar Coordinate effect & Offset effect to between the Transform and Polar Coordinates effects, THE GAP DISAPPEARED!!
Meanwhile, it turns out to become a more interesting situation here LOL
Gaps appear at both sides on the circle.
Attachments
12.png
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Re: [HELP] Polar coordinate problem with transform

Postby star+circle on 06/9/2015, 4:50 am

Found a simple solution: Precomp the layer and the transform effect, ensuring the image still goes all the way to the edge and then apply Polar coordinates to the precomped layer. i.e. the Transform effect in inside the precomp, Polar coordinates outside.
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Re: [HELP] Polar coordinate problem with transform

Postby Gosh_Uhfa on 06/9/2015, 11:01 pm

star+circle wrote:Found a simple solution: Precomp the layer and the transform effect, ensuring the image still goes all the way to the edge and then apply Polar coordinates to the precomped layer. i.e. the Transform effect in inside the precomp, Polar coordinates outside.

IT WORKS FINALLY!!!
Thank you so much for helping!!
Although I am still confusing about why would this happened, the gap is now gone.
I follow the tutorial step by step, any idea why would this problem happen?
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