Problem with the edges of my shapes

[abstract_videography16B8]

Hi everyone,

I'm having a problem where my shapes are not aligning correctly.  I have two shapes that have the same Y-position, anchor point, and scale values.  However, when the shapes are placed side by side, the top layer is larger than the bottom layer (window view is zoomed out 50%).  However, when I zoom in 3200% the layers look exactly aligned.  Anyone suggestions what the problem might be?  Thanks     

[Dave_LaRonde]

If you didn't DUPLICATE the shape layer, they're probably two different sizes.

[abstract_videography16B8]

Thanks for the quick reply Dave.  However they are duplicated layers. I recreated the issue.  In this instance, I duplicated 4 layers with the anchor point all in the middle right edge.  So pretty much a simple animation for the X scale value going from 0 to 100% (only X dimension). I might be going crazy, or my eyes are just real bad.  But, if you look at the zoomed out 50% image, the red solid looks smaller than the white and blue solid.  Even though they have the exact same properties, if you look at the corners of the red solid it looks out of place.  Also, with the 3200% zoom in image, they look exact same size. I might have to take a break from the computer screen, and come back to look at it again.

[Dave_LaRonde]

Changing the scale will do that.  AE doesn't scale at pixel-perfect increments.  It uses subpixel rendering for fractional pixel values.  So what you see is perfectly natural.

Relax and get on with your project. all is well.

[abstract_videography16B8]

Man this was driving me crazy.  Thanks Dave! 

[Roland Kahlenberg]

You wrote - "But, if you look at the zoomed out 50% image, the red solid looks smaller than the white and blue solid."

However, the "50% zoomed out" image you posted shows something totally different. You are correct that something is amiss and the facts currently show that it is YOU! lol

Settle down and post more info,but first, double check them.

I've just seen from you Timeline screencap that their Scale values are different. Why is this info not relevant to their varying sizes?

[abstract_videography16B8]

Hey Ronald,

haha yea I need to just chill.  But, I found something similar to this issue on youtube. 

If you go to the 13:16 mark of the video, he kind of explains the issue regarding pixel. 

https://www.youtube.com/watch?v=PmuY1XpFEbY

[Roland Kahlenberg · Accepted solution]

From the video, it's not clear if his issue is related to multiple layers sharing the same pixel space. I've also clicked on your image and taken a look at it at this higher rez and I now understand your problem.

This is an old, well-known issue that occur not just with Shape Layers but all types of layers and it has to do with AE having to resample an image on each frame.

When the (AnchorPoint+Position)/2 equals a number that is not an integer, you will get this edge softening issue.

Try these steps to see what I'm talking about -

1) create a 400x400 Rectangle, Shape Layer

2) at default, the Anchor Point for Shape Layers will be {0,0} - leave it as it is

3) Position will be at [960,540] ,at its default value, for a 1080HD rez comp.

4) zoom in to 1600%, to the left-top edge of the comp

5) in the Timeline, display the AnchorPoint and Position properties and set the AnchorPoint's value to [0,.5]

Notice how the top edge now has a bit of edge softness?

Now change the AnchorPoint's values to [.5,0] and notice how the same issue now affects the left edge.

Leave the AnchorPoint value as it is and change the Position property value to [960.5,540] and notice how the edges are now clean and tight again.

Understanding how AE resamples images is key to solving this common problem

(AnchorPoint + Position)/2 must equal an integer in order for AE to draw perfectly clean images; and edges.

[abstract_videography16B8]

Ronald, Thank you so much!  I thought I was losing my mind trying to fix this issue from trial by error.  Sorry if this was a newbie type question.  But problem solved! Have a nice weekend

[Roland Kahlenberg]

WAIT!!!
I'm not done yet!!!
I've not covered Scaling yet and I should add clarity that {Ap+Pos)/2 applies for X and Y, separately — as in the first two examples I showed you earlier.

Scaling makes things more complicated since it affects the edges of the layer and the edges may be placed such that they mimic the case where (Ap + Pos)/2 is not an integer.

For this, set the AnchorPoint of the 400x400 rectangle, Shape Layer to the center of your Shape Layer - ALT+CTRL+HOME. Then set the Shape Layer to the center of the Comp - CTRL+HOME.

Dive into your Shape Layer's Transform properties (not to be confused with Layer>Transforms) and zero in the AnchorPoint and Position properties.

Now, twirl all the properties up and display only Layer>Transforms for Scale, AnchorPoint and Position.

Scale up and down to your heart's content, without adjusting AnchorPoint or Position and you'll notice that the the edges stay sharp regardless of the scale value for as long as the Scale value is made up of integers. If you put in a number such as 22.1%, a non-integer then the edge softness occurs.

To experiment further, to obtain a deeper understanding, set Scale to [100,100]. Change Position's value to [900,500]Then adjust Scale to different integer values. You should see no difference here.

The moral of the story is in understanding layer resampling in AE and that scaling is not the real cause of such issues since scaling can result in crisp edges as long as the Ap and Pos formula is adhered to. Further, a Shape Layers, internal Transform>AnchorPoint and Position values are also calculated in determing the Ap  and Pos formula.

And if you misspell my name again, for the thirds time in a row, I will hound you in your nightmares tonight!!! 😉

[abstract_videography16B8]

I will make sure every number I use for now on will be integers.  Also I really do need to get my eyes check Roland.  Sorry about that!  Will have nightmares tonight thinking of non-integer number.