Procedural Texture - Pixels Offset

[telemax]

Hi,

Is it possible to offset pixels along the X and Y axes, using a procedural texture?

 

[NotMyFault]

Not fully sure how to interpret your question, but i hope my reply covers all possible interpretations;-)

• PT expressions can contain coordinates like x,y, rx,ry, ox,oy. Using r or o as prefix gives you the option to drag an offset my mouse, but 
• PT expressions can contain RGBA values (or CMYK / LA/LB etc depending on color format), but
• these values are always bound to the pixel position.
• To my knowledge, you cannot „read“ the RGB value of another position in PT filters.
• As a limited workaround, you may use „apply image“: It allows to access exactly two layers (called source and dest), and if you move one layer according to your offset, you can blend the RGB values of two layers.
  This workaround is limited to a fixed offset for all pixels of the layer, and destructive usage.

If you raise a feature request adding this functionality to Photo, i will be more than happy to add my vote 👍🏼

[telemax]

Thanks, i was only able to get a white image with offset by one of the coordinates.

 

But I'm trying to move the layer to the side, some distance along X and Y (random offset).

 

[NotMyFault]

i don’t thing  that PT filter is able to move pixels. 
 

Equations filter will do what you need. Unfortunately there is no live version available

https://affinity.help/photo/English.lproj/pages/Filters/filter_equations.html

[telemax]

Thanks, it works in Equations. I made an offset of 500 pixels.
Does anyone know if it is possible to make a shift by a random number of pixels, within the limit?

[John Rostron]

Equations does not have an expression for random numbers. It has a noise expression, but I still have not yet worked out what it does to an image. You could try something like:

x=x+noise(x,y)

y=y+noise(x,y)

If you just want an offset, you could try the Affine Transform.

John

[John Rostron]

@telemax, I have just tried this on an image.  You need to multiply the noise function by around 20 to 100 to get any useful effect. It does produce quite a nice random artistic effect though.

Original:

After, with noise*50:

John

[telemax]

Thanks, I checked it out. x+noise(x,y) and y+noise(x,y) create small noise on the image, including image edges.
It also works x-noise(x,y) and y-noise(x,y)

a little explanation

image offset works more simply, x-50, y-50 or x+50, y+50

 

[telemax]

1 hour ago, John Rostron said:

You need to multiply the noise function by around 20 to 100 to get any useful effect. It does produce quite a nice random artistic effect though.

Wow it really cool effect! But I just wanted to offset a lot of selected layers, in random X and Y directions.

 

[NotMyFault]

You could try displace filter in combination with a crafted layer

[telemax]

When searching for one solution, there are other interesting effects 😁

 

[R C-R]

4 hours ago, John Rostron said:

You need to multiply the noise function by around 20 to 100 to get any useful effect.

FWIW, instead of a number, using w in the x equation & h in the y equation, plus Parameter A & B multipliers seems to work well regardless of document dimensions. So something like this:

x= x+noise(x,y)*w*a

y= y+noise(x,y)*h*b

Changing the Extend Mode to Wrap or Mirror is also interesting.

[telemax]

I think I was able to get a dependency of A from B.

x-noise(x)*w*a*b
y-noise(y)*h*b