On 3/16/25 03:21, William F Pokorny wrote:
> So the issue has to do with overlapping regions of complete transparency 
> I guess. Wonder, does the ior 1+epsilon trick not work in v3.7? Hmm, 
> maybe with the spherical camera more rays hit the surface parallel to 
> surface normal? Don't know.

It just came to me what is likely going on.

The disc has an infinite inside so the 'interior ior' only kicks in on 
the fist disc intersection. All the disc surfaces seen after that first 
are inside other discs and also have the same ior - so there is no 
further refraction, but rather we get again transmitted rays. In other 
words, the trick doesn't limit the recursive depth on ray surface 
traversals in this case because it only bumps the max trace level by 
one. We get Max Level: 2/6 rather than 1/6 - and we were after 6/6.

Bill P.

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On 3/16/25 08:36, Bald Eagle wrote:
> I would think the lines would be curved in that instance?

I guess what I was thinking is that off to the left and right the disc 
intersections would become perpendicular where one of the two discs has 
passed behind the forward directional plane - and both discs are 
somewhat near the camera location. But, I admit I'm not sure I've 
imagined the situation correctly.

> 
> Just out of curiosity, I was wondering what the actual overall scene looked
> like, so once I wrapped my head around the coordinate system and
> camera-to-look_at orientation, I was able to pull the camera back and look down
> over the entire undistorted market.
> (see attached)

Cool. :-)

Bill P.

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On 16/03/2025 04:27, yesbird wrote:
> This is what I got with theradius = 0.1 and no crash.
> -- 
> YB

The charm of these mystical cyberpunk-like images forced me to start
rendering complete animation and this is the first 11 seconds
(334 frames of 3204x512 resolution) with cylindrical projection and
forward-backward loop:
https://povlab.yesbird.online/pb/

Rendering in progress ...
--YB

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yesbird <sya### [at] gmailcom> wrote:


> rendering complete animation and this is the first 11 seconds

> forward-backward loop:
> https://povlab.yesbird.online/pb/
>

> --YB

Super nice job, Sergey.  :)

This is pretty much what I envisioned Paul was shooting for when I saw that all
of the points were a sort of firefly glow.

I just did a quick render using "puffs" that I used in place of spheres.

It adds a peaceful, ethereal, Christmassy feel.

So now I'm thinking that if there was a way to use a collection of actual
snowflake shapes and have them appear, fall a sort way, then fade out - in a
cycle centered on their locations, that might make a cool "animated animation".
Or it might look like a total nightmare of a mess  ;)

- BW

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Attachments:
Download 'scenewithpuffs.png' (625 KB)

Preview of image 'scenewithpuffs.png'

Also:

Since we have trace (), we can do a synthetic / virtual LIDAR to take any
geomtric scene and place similar points.

What we DON'T have, is a combination of trace () and eval_pigment () to return a
color.

I suppose there are a number of workarounds that we could do there...

3D to 2D reverse projection (screen location macro)

Scan all of the objects in the scene sequentially with trace, and assign color
based on which object gets hit. (ugh)

Render the geometric scene and use that as an image_map for eval_pigment, and
use trace () in a sort of orthographic scanning mode.

I think the last has the most merit.

- BE

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On 16/03/2025 21:44, Bald Eagle wrote:
> Super nice job, Sergey.  :)
> 
> This is pretty much what I envisioned Paul was shooting for when I saw that all
> of the points were a sort of firefly glow.
> 
> I just did a quick render using "puffs" that I used in place of spheres.
> 
> It adds a peaceful, ethereal, Christmassy feel.
> 
> So now I'm thinking that if there was a way to use a collection of actual
> snowflake shapes and have them appear, fall a sort way, then fade out - in a
> cycle centered on their locations, that might make a cool "animated animation".
> Or it might look like a total nightmare of a mess  ;)
> 
> - BW

Thanks, Bill, it was not a "rocket science" task, having Three.js, a
powerful server and such rich data in hands.

I like your idea about snowflakes - winter in HK looks excellent !
Animated animation sounds intriguing, and looks like a lot of space for
experiments. If you will send me a scene, I'll do the rendering.

Now I am working on a stereo version with VR support, for those who have
a headset (static images at first). Btw, this is the reason why I am
prefer HGPovray - it has a stereo camera.
--
YB

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On 16/03/2025 21:51, Bald Eagle wrote:
> Also:
> 
> Since we have trace (), we can do a synthetic / virtual LIDAR to take any
> geomtric scene and place similar points.
> ...

Really, and by applying different objects to points we can produce
fantastic effects ! I like this idea very much and can assist as I can.

Quick googling shows that colorization of point clouds is not a trivial
task, but there are different approaches and solutions to choose from.
Interesting, how did PB solve it in his scene ?

Let's try ?
--
YB

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"Bald Eagle" <cre### [at] netscapenet> wrote:
> "Paul Bourke" <pau### [at] gmailcom> wrote:
>
> > Thanks for the suggestions. I am now rendering in 3.8, only takes about 20s and
> > that's with an even bigger inc file. But speed isn't an issue for me, at least
> > with 3.7 since I can distribute it.
>
> Well, I was juggling making the kid dinner + other stuff + Bourke-level POV-Ray
> creativity, so I wanted to get a finished render so that I could get a better
> overall idea of what was going on.
>
> > The 3.8 I downloaded has the gui (MacOS), is
> > there a pure command line for 3.8? Can't efficiently do a distributed render
> > with the gui.
>
> Yes Sir.
> I just ran [Path] pvengine64 /RENDER scene.pov, and that seemed to work fine
> under M$ Win 7
>
> > See previous message, tried cylinders and spheres (3.7), same problem.
> >
> > There are also nasty defects in the 3.8 render (discs), see attached example
> > frame. Strange they are mostly on the right half, it's those narrow dark
> > slivers. Perhaps they are a cue to what's happening.
>
> Dunno.  If they're disks or something, maybe somehow they got oriented wrong,
> and they're dark colors in front of light?
>
> I just tried again with spheres that are scaled by 0.01 in x, so that they
> resemble your original disc.  Can't tell if the lines are there.
> What resolution are you rendering at?
>
> - Bill

No problems with spheres.
There is only one light source, it's at the camera.
I can't imagine misorientated discs, the normal is the vector from camera to
point position.

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"Bald Eagle" <cre### [at] netscapenet> wrote:
> "Bald Eagle" <cre### [at] netscapenet> wrote:
>
> > I just tried again with spheres that are scaled by 0.01 in x, so that they
> > resemble your original disc.  Can't tell if the lines are there.
> > What resolution are you rendering at?
>
> "Just download the render at look at the image size, Bill."
> <eyeroll>
>
> Take a look at this and see what you think.

Except that's not the look I want. The "ghostly" effect is the goal.

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yesbird <sya### [at] gmailcom> wrote:
> On 16/03/2025 04:27, yesbird wrote:
> > This is what I got with theradius = 0.1 and no crash.
> > --
> > YB
>

> rendering complete animation and this is the first 11 seconds

> forward-backward loop:
> https://povlab.yesbird.online/pb/
>

> --YB

Looks good. What was the magic sauce? 3.7 or 3.8?
I'd be much happier if I could use 3.7.

The look I currently have is with 3.8, sample frame attached. Final render will
be 12816x2048, and a omni directional stereo pair. Should look good in a 360 LED
stereo cylinder.

This one has many more points, 1500K.
I vary theradius depending on distance from the camera, with some bounds.
Added light falloff and other stuff.

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