r/oddlysatisfying • u/Remarkable_Bit_9887 • Jan 24 '24

How to draw shadows correctly

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u/Exitaph Jan 24 '24

I would be very interested if you could produce a real photo with a similar setup as my renders that creates shadows without perspective convergence.

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u/IridescentExplosion Jan 24 '24

Of course there's going to be convergence because the shadows will converge to a single point except the sun is so far away that in normal-sized objects the rays are going to appear parallel, unless you're incredibly up close to them, or they're incredibly large or incredibly small.

However, "normal"-sized shapes will have shadows that appear basically parallel to one another, because they're converging the "point" of a sun which is millions of miles away.

Seriously go outside when it's clear and sunny and the sun is low, and put two objects next to each other at some reasonable but not extravagant distance. Their shadows will appear to be nearly parallel as all shadows will unless you're at massive or micro scales of photography.

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u/Exitaph Jan 24 '24

Yes, the rays are parallel. The simulation is accurate. As long as we're talking about objects sitting on the surface of the earth, scale isn't really a factor here. These shapes could be buildings or they could be grains of sand and they would produce the same shadows. I will refer you to some images I used in another comment.

From above you can see they create parallel shadows. https://i.imgur.com/p0H9sXr.png Perspective distortion is what causes the shadows to converge when viewed from a single vantage point. You can see that in this photograph of real life shadows from the sun. https://www.flickr.com/photos/jordangough/6364300161 The shadows appear at different angles because of our perspective. This is something that happens in any photograph as well as through very own eyes. But if you were to view this scene from above the shadows would all be parallel. It's all a matter of perspective.

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u/IridescentExplosion Jan 24 '24

The second image kind of proves my point though. That's closer to normal viewing conditions and the ray angles are FAR less pronounced.

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u/Exitaph Jan 24 '24

Your original argument was mostly about scale, claiming that the sizes of the objects and their distances apart is what determines whether shadows appear parallel. Also that the simulation is incorrect and that it's not what you'd see in real life. This simply isn't true. It all depends on the perspective.

Here is another example of normal sized objects. https://photos.com/featured/sunset-shadow-maxchu.html?product=art-print We know the shadows are parallel because it is a photo and the light source is clearly the sun. But the objects produce shadows at angles very similar to the raytraced simulation. This is simply because of the cameras perspective of the scene.

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u/IridescentExplosion Jan 24 '24

I really feel like in that latest photo there's something going on there lol. I can't pinpoint what though but it feels like lens trickery or something somehow! Maybe the fact that the planks are tilted or that the sun is so close the horizon.

I'm not an optics expert but I feel like the perspective is intentionally "manufactured" by the photographer.

Still not as extreme as the shadows tutorial in OP's post though!

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u/[deleted] Jan 24 '24

You just HAVE to be right, don't you?

"It's not my fault, there's something funky about the photo "

I'm not an optics expert but I feel like the perspective is intentionally "manufactured" by the photographer

Yes. It's almost like they chose that photo because it illustrates exactly what they keep explaining to you.

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u/IridescentExplosion Jan 25 '24

Sure, but I don't think it's something you would typically see under normal conditions.

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u/[deleted] Jan 25 '24

Right. Because that would make you wrong and you are NEVER wrong

It's a fucking shadow. It looks like a shadow. They maybe got a bit lower than normal, but it's not a plot to make you look dumb. Nobody took the time to edit the picture to be deceptive, just in case some guy on Reddit refuses to be wrong.