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------------Problem----------------
Took a close up photo of a computer monitor and would like to replicate the effect in inkscape but am not sure how - my attempts are not working.

enter image description here

-------------What I did--------------
I took a black canvas and made a grid, filled it with circles leaving very small gaps for lines to be formed.

Then I used "object to path" I got the grid I want but it's flat.. I want it in perspective.

I made a rectangle in perspective.. and used "perspective" in "extensions" while having both the rectangle and the grid selected.

I got a dialogue box says "working on perspective please wait" I waited for a few minutes, the dialogue box disappeared and nothing has changes w/r to the grid and rectangle

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  • I have added the details in the question now. Can you please review? Thank you Commented Oct 17, 2020 at 17:54
  • Thank you for the edit Jahnavi. That should allow users to target answers much more efficiently. I cleaned it up slightly merely because I'm familiar with formatting as it relates to this site.
    – Scott
    Commented Oct 17, 2020 at 17:58
  • Oh I was wondering how it appeared neat all of a sudden. Thank you so much(人 •͈ᴗ•͈) Commented Oct 17, 2020 at 18:03
  • That's a Moire pattern. Camera sensor pixel density and computer screen pixel density interfere. Camera lens distortion makes the screen pixel density non-uniform in the image so the interference pattern is complex. If you happen to be a little musical you maybe have noticed how 2 simultaneous a little out-of-tune musical voices wobble, the sound volume swings at the difference of the voice frequencies. In math the phenomena is the same in your image except images do not happen in time, but along surface dimensions. To get the same effect you need 2 only a little different grids layered.
    – user82991
    Commented Oct 17, 2020 at 18:04
  • (continued) Your screen will be a guest star in the show. To have only 2 players in the game you should draw only one grid or draw 2 grids with much lower densities than tour screen pixel density.
    – user82991
    Commented Oct 17, 2020 at 18:09

1 Answer 1

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Try this:

  1. Draw two lines with a thin stroke, one at the top and one at the bottom of the picture.

  2. Select both lines and use the Interpolate Extension, to create hundreds of lines.

Update: after the OP's inclusion of an image, it's clear now that the desired effect is to create a Moiré pattern effect.

This can be done using the same technique as above, then applying an Envelope Deform filter to the lines. This will set up a Moiré interference pattern with the pixels on your display. Obviously how this looks will depend on what zoom level you are viewing it.

Here's an example of what it looks like. This is a 500 line interpolation, with an Envelope Deform filter, and a little rotation applied.

enter image description here

And here's what it looks like when placed over a raster image

enter image description here

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  • Also I want the lines to be in perspective. How can I do that? When I use perspective it's not working and too many paths are slowing down my laptop so much Commented Oct 17, 2020 at 17:57
  • @Jahnavi You can draw the lines in perspective to begin with, to lie flush with the edges of the image. Incidentally the pattern on the image you have now included is an example of an interference pattern. To get that, you would need another set of fine lines at an angle to the first set.
    – Billy Kerr
    Commented Oct 17, 2020 at 18:11
  • If there are too many paths it may lead to a slow-down in vector software. There's no real way to avoid that. If this is an issue, consider using a raster image editor instead. GIMP has a Newsprint Filter which could be used to generate scan lines over an image.
    – Billy Kerr
    Commented Oct 17, 2020 at 18:14
  • 1
    The wanted complex pattern appears if the first line of the interpolated set is a little curved and the last line is also curved, but to the opposite direction. That simulates distortion in camera lenses.
    – user82991
    Commented Oct 17, 2020 at 18:22
  • @user287001 - Inkscape's envelope deformation filter would work for that. In fact one set of lines would be enough since it would set up a Moiré interference pattern with the pixels on a display anyway.
    – Billy Kerr
    Commented Oct 17, 2020 at 18:32

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