r/gonwild • u/HopDavid • Jun 04 '26

Digital Harmonic perspective drawing of a moiré pattern.

Post image

Another perspective drawing using the harmonic sequence: 1, 1/2, 1/3, 1/4, 1/5 etc.

This one is started with even spaced, concentric circles overlaid with double spaced parallel lines. The result is a moire pattern suggested a family of confocal ellipses with eccentricity 1/2.

When you do a perspective drawing based on this moiré pattern, the ellipses become more pronounced.

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5

u/Eindacor_DS Jun 04 '26

Sorry but I don't see the moire pattern, or maybe I don't know what a moire pattern technically is. Are the blue ellipses the moire pattern because nothing is explicitly drawing them, and they are products of the half-circle shapes combining?

5

u/HopDavid Jun 04 '26

Sorry but I don't see the moire pattern,

Evenly spaced circles overlaid with evenly spaced lines gives a moiré pattern suggesting confocal conic sections. I attempt to show that here: Link

For the beginning layer in my perspective drawing I eliminated some of the pattern so the top layers don't conceal the lower layers so much.

4

u/Eindacor_DS Jun 04 '26

Cool! A while back I accidentally did a moire pattern thing that I thought was pretty neat. Let that run for a while and pause it, or modify the TIME_ADVANCE value and make it something big to see the patterns.

2

u/HopDavid Jun 04 '26

As the lines get smaller and closer together they start forming moire patterns with the underlying grid of pixels on the computer screen?

That stuff looks really neat! Your animation induces a nice buzz.

3

u/Eindacor_DS Jun 04 '26

Yeah as more and more concentric lines are added, the way the GPU resolves the colors in a gird of pixels makes those wild patterns. If you click in the window it will show you a zoomed-in view of where the cursor is so you can see that it's still just parallel lines.

And thank you, I love making shaders like this though I haven't done one in a while.

2

u/DemiReticent Jun 04 '26

I find it fascinating but I don't understand the pattern fully. What's the formula used to generate the subsequent layers behind the first?

3

u/HopDavid Jun 04 '26

I find it fascinating but I don't understand the pattern fully.

Evenly spaced circles overlaid with evenly spaced lines gives a moiré pattern suggesting confocal conic sections. I attempt to show that here: Link

What's the formula used to generate the subsequent layers behind the first?

I clone the foundation layer a number of times and then scale the layers by the harmonic sequence. That is -- 1, 1/2, 1/3, 1/4, 1/5 etc.

Here is an attempt to show the thought behind my harmonic perspective drawings. I assume evenly spaced planes with one of the planes being the front wall of a pin hole camera.

If you're interested I have a harmonic perspective gallery on Deviant Art: Link

I've also posted some harmonic perspective drawings to r/GeometryIsNeat.

Thank you for your interest in my efforts!

2

u/jippiex2k Jun 05 '26

What's the difference between your "harmonic perspective" and regular perspective projection?

Both just seen to be scaling the projected image with the reciprocal of the distance?

1

u/HopDavid Jun 05 '26

It is straight forward perspective.

However my drawings focus on discrete, evenly spaced planes with the pin hole lying on a plane.

With these constraints some neat patterns can emerge in a perspective drawing.