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njfeathe85  
#1 Posted : Tuesday, September 22, 2020 12:24:20 AM(UTC)
njfeathe85

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Hi All

Firstly apologies if there is already a topic on this, I have tried searching but as yet I've not found anything specific enough to satisfy my questions.

I am wanting to know how the position values of an overlay relate specifically to what is happening on screen. So for example, if I have an overlay and I want to move it to the right most edge and top most edge of the screen what value am I to enter? Trying to do it with the slider is not entirely accurate.

My second question is from where on the source does it take the measurement? Is it x0,y0 (top corner) or centre mid?

If just using the pan X it seems the left most value is -2 and the right most value is 2.

Finally, what unit are the values? They dont appear to be a metric (or imperial measurement) nor do they appear to be percentage or pixels.

TIA
Paul Fuhrmann  
#2 Posted : Tuesday, September 22, 2020 12:58:58 AM(UTC)
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So what i learned about the Position Maths is as follows:

All Graphical Inputs are Centerd by defaultt, and scaled till one input boarder reaches one canvas boarder.

The Default Anchorpoint for Object seems to be the center of the object (pre crop if you crop try it)

How to figure out;

Use a 1080p canvas, Create a 1080p input

Scale the Input to 50% resulting in 960x540 px
-Input keeps centered, if anchor would be top left it would stick to this top left corner.

Then set 25% Horizontal movement: The Input whill move to the border.
-Now no gap should be seen. on one side while the widht of the screen is half the widht of the canvas.

leftborder -> 480px |Anchor Input| 480px |CenterCanvas| 960px <-right border

This is the test how it calculates.

Have Fun
thanks 1 user thanked Paul Fuhrmann for this useful post.
njfeathe85 on 9/22/2020(UTC)
njfeathe85  
#3 Posted : Tuesday, September 22, 2020 1:19:45 AM(UTC)
njfeathe85

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Thanks mate.

I've actually just found a part of one of the tutorial videos for the Squeeze/Merge effect that explains a formula for setting the source to the edges of the screen. (https://youtu.be/uCyAUZeoFQo starts at around 8mins 30secs).

Basically -

Set the zoom of your overlay to what you want. As 1 is the size unchanged it can be thought of as 100%, so you can take it down in percentage, so 20% reduction is 0.8, 30% is 0.7 and so on.

To then set the pan tilt the formula is "1-Zoom". So if Zoom is a 20% reduction (0.8) then its "1-0.8=0.2 and you would use -X & -Y to adjust to the left and bottom of the screen.

So to move the source around it be as follows -

top left - X=-0.2, Y=0.2
bottom left - X=-0.2, Y=-0.2
Top Right - X=0.2, Y=0.2
Bottom Right - X=0.2, Y=-0.2

And if you wanted your source to align top or bottom edge but stay central then X=0 and Y=1-zoom as above.

This makes it easy to line up a VT/Presentation source with a camera and a title etc.
thanks 1 user thanked njfeathe85 for this useful post.
Papo on 9/23/2020(UTC)
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