It's an incredibly calming experience, I've listened to the audiobook over 10 times before sleep. Highly recommended.
[0] which used footnotes to great effect
But I couldn't get into Piranesi at all. The first few chapters never seem to actually go anywhere. It got terrific reviews so maybe it's just too abstract for me.
I think this is a key point that people are often unaware of. For instance, whenever I see a modern artist who has painted photorealistic art, I read discussion about how amazing it is that this artist can paint something so perfectly life-like, and the Renaissance artists were clearly inferior, since they couldn't paint with such skill.
Besides the obvious discussion about the purpose of art, the other question is whether a photorealistic painting is actually more "lifelike?"
Sure, it represents the world exactly the way that a camera sees it, but does it represent the world exactly as we see it? With our human brains we are filling in details, we are focused on the subject of the painting, we are distorting, we are re-mapping shades of color to what we know they ought to be. "Lens blur" in particular isn't remotely the way our eyes perceive the world: our eyes can never roam around the unfocused parts of our own image, rather we ignore the blurry parts unless we specifically try to notice them, and anything we try to focus on becomes sharp.
So I appreciate the authors recognition that Piranesi's perspective may indeed be closer to how we perceive the world than "correct" perspective.
Unrelated to perspective: Artists often put more detail in places that you're "supposed to" look at, and leave other things more as a blurry sketch, and our eyes naturally don't linger on those parts. What's interesting to me is that I can often recognize AI art by the way it doesn't make use of this, it tends to make everything equally detailed.
[1]https://bookshop.org/p/books/seeing-like-a-state-how-certain...
> The distinctive feature of Piranesi’s perspective trick is that when you have a series of similar objects receding into the distance, such as houses or arches in a bridge, the nearer versions are just drawn as larger versions of those in the distance
This makes so much sense. When nature presents me with a series of identical arches, that is how I'm going to interpret them. Not as the geometric shapes that are actually projected onto the backs of my eyes.
Another difference: In human sigth you can only focus on the center of the vision field, while on a photograph you can look at unfocused points and observe the distortion on the edges of the picture. Human observation (like looking at the bridge in the pic) is really a series of observations where we move the focus.
[0] https://dev.epicgames.com/documentation/en-us/unreal-engine/...
I wonder what would happen if we'd render videos using it, and maybe games? Could this be a solution to better graphics? Would movement ruin it? Please tell me!
Examples
Panini: https://wiki.panotools.org/File:Ben_Equirectangular_panini.j...
Equirectangular: https://wiki.panotools.org/File:Big_ben_equirectangular.jpg
Full list: https://wiki.panotools.org/Projections
they're on 1.35 right now which is a bit out of date (lifecycle - https://www.mediawiki.org/wiki/Version_lifecycle) but an older branch of MMV should work fine on 1.35
Hmmm
> The mathematics of this is quite simple
If so then surely a program could be written
https://github.com/brunopostle/piranesi
The problem is that it is a method for projecting a rectangle, not a full 3D scene. I can imagine though that it could be extended to a full projection if you specify a central axis along which the perspective trick happens.
So maybe the author was just saying if the work was drawn with "true" perspective throughout, there isn't a programmatic way of converting the entire thing over to Piranesi. That's at least how I read it, I'm curious about it too!
Unreal Engine has support for it as a post-processing filter[1], but I don't know of any games using it.
[0]: http://tksharpless.net/vedutismo/Pannini/panini.pdf [1]: https://dev.epicgames.com/documentation/en-us/unreal-engine/...
"Normal homography perspective transformation produced in GIMP. Note how squashed the buildings at the right and left are when taken in isolation"
The building on the right is squashed, in isolation. When you take the building by itself (in isolation), it is indeed wider than the picture above, but it is also the same height, i.e., squashed.
Here's a problem. The textures have to be put through a perspective projection. As in every pixel.
It's possible to cheat. You can simply use a bicubic stretch or even linear. It really shows up when the polygons are large and they rotate to create deep perspective. You see an artifact whereby the center of the texture does not stay centered on the polygon as it rotates.
https://webglfundamentals.org/webgl/lessons/webgl-3d-perspec...
https://aaronhertzmann.com/2024/06/10/perspective-distortion...
https://aaronhertzmann.com/2024/09/09/dvc-multiperspective.h...
TIL.
It makes absolute sense, but I never even thought about doing it that way. I was trained as an artist, and I always did perspective the "classic" way. It's entirely possible that this might not work on some subject matter, but it works great on buildings.
> But here is the same elevation drawn using correct rectilinear perspective. I hope you will agree that the Piranesi version is much more legible, the furthest house above is easier to see and the nearest house isn’t horribly distorted as it is below.
The section with this bit has some pictures that really illustrate the effect.I wish there was an easy photoshop way to recreate this
I don't know how to confirm this; the distortion just feels similar to me.
Well given that this is HN, if there's any forum where somebody has experience contributing to GIMP, it should be here. Any takers?