@DMGregory two different sources of error in the 2nd image:

A) neglected to update the location for a gradient calculation in the 4 pixel at a time version. Essentially pixels 1,2,3 were using the gradient math as if they were pixel 0.

@Pikalek Does it really look like a palm tree, or am I biased to see a palm tree there?

B) I had an early out check to bail if a pixel had already been written (because there's overdraw along the lines). On 1x it's fine, but at 4x it can happen that pixel n was already written & pixels n+1 to 4 get skipped. This led to the blacked out sections.

(or even a headless dancing person..??)

@Vaillancourt The shaders from the far realms show our mortal minds many things! Mwhahaha!!

I bet combining this with psychedelic substances will reveal unknown secrets from the depth of our minds!

And also yes, I see tropical leaves &/or Salvador Dalí versions of barrel of monkeys.

@Vaillancourt I read a very interesting paper about why certain meta images seem to be more frequent results of psychedelics. Had something to do w/ low level brain hardware & image processing.

It got me wondering if that's part of why I find working with these renderers to be so captivating.

Ahhhhhh! That makes sense. Thanks for explaining it!

Ha, you have read more than I did about it. I find it fascinating that we're so advanced in terms of knowledge about the human brain, yet we know so little about it.

Yes! The irony is delicious! The more we learn about it, the more hidden depths we find.

Offhand, I can't seem to find the paper I was recalling, but if/when I dig it back up, I'll share a link.

:+1:

I think it was What geometric visual hallucinations tell us about the visual cortex. The same team also did Geometric visual hallucinations, Euclidean symmetry and the functional architecture of striate cortex which I haven't yet looked over, but looks interesting (albeit rather crunchy to me as I'm not very well versed in this field).

> Many observers see geometric visual hallucinations after taking hallucinogens such as LSD, cannabis, mescaline or psilocybin; on viewing bright fickering lights; on waking up or falling asleep; in “near-death” experiences; and in many other syndromes. Klüver organized the images into four groups called form constants:(I) tunnels and funnels, (II) spirals, (III) lattices, including honeycombs and triangles, and (IV) cobwebs. In most cases, the images are seen in both eyes and move with them.

> We interpret this to mean that they are generated in the brain. Here, we summarize a theory of their origin in visual cortex ...

Hey that's an aspect I've never considered: both eyes see them, so yeah, the brain is playing tricks!

Yeah, there's some really neat stuff packed in there.