Ray Tracing with POV-Ray: 25 scenes in 25 days (2013) • Hacker News Board

Re: Ray Tracing with POV-Ray: 25 scenes in 25 days (2013)

#31

Post by michal_f » Fri, May 01, 2020, 6:05 PM UTC

tlb wrote: post #30

klodolph wrote: post #29

Earlier quoted context omitted.

I think you may have missed what the parent comment was saying—that the polygons can be made smooth before render time. This is not a question of just faking it with normals. Instead, you can actually just work with a polygonal mesh and then post-process it to make it actually smooth. The classic technique for this is Catmull-Clark subdivision. If you think polygons on screen are offensive, you can just run the algor…

Yes, but then any edges that should have been sharp get rounded too.

You can have sharp edges and vertices with subdiv surfaces.

Re: Ray Tracing with POV-Ray: 25 scenes in 25 days (2013)

#32

Post by elihu » Fri, May 01, 2020, 6:06 PM UTC

jordache wrote: post #9

how is POVRay used in modern workflows these days? It's extremely counter intuitive to articulate a 3d scene in code. Maybe for some applications, exactness in the 3d scene via code is useful.

As far as I know, it's not. The turing-complete scene description language and the many ways of representing geometry that makes POV-Ray so powerful and fun to use also makes it very difficult to interoperate with other tools.

POV-Ray is mostly used by hobbyists, students, and people who need to visualize some data and need a tool that can be easily scripted for their needs.

Re: Ray Tracing with POV-Ray: 25 scenes in 25 days (2013)

#33

Post by klodolph » Fri, May 01, 2020, 6:11 PM UTC

I loved POV-Ray in the 1990s and early 2000s. The thing is—it’s ridiculous to try and make something remotely complicated or organic with POV-Ray, unless you are using some modeling program that can export to POV-Ray format.

POV-Ray scenes were dominated by procedural textures and geometric primitives, for the most part. The rendering engine was very strong, and supported all sorts of features like area lighting, depth of field, motion blur, global illumination, caustics, volumetric lighting, etc. All of these were supported way back in the day before they became more common in other engines, and of course, using these features made your render times horrific back on early-2000s single-CPU machines.

The way a lot of us did modeling in POV-Ray was with a pencil and some graph paper. Without a good modeling program, you were setting yourself up for a ton of work. So I’d try to get the most out of simple models, and make it look as good as possible with lighting.

Funny enough, if you are used to CSG then you may need some time to adapt to modern workflows. Blender supports CSG, of course, but there are some caveats that you should pay attention to.

Re: Ray Tracing with POV-Ray: 25 scenes in 25 days (2013)

#34

Post by [deleted] » Fri, May 01, 2020, 6:16 PM UTC

tlb wrote: post #30

klodolph wrote: post #29

Earlier quoted context omitted.

I think you may have missed what the parent comment was saying—that the polygons can be made smooth before render time. This is not a question of just faking it with normals. Instead, you can actually just work with a polygonal mesh and then post-process it to make it actually smooth. The classic technique for this is Catmull-Clark subdivision. If you think polygons on screen are offensive, you can just run the algor…

Yes, but then any edges that should have been sharp get rounded too.

[deleted]

Re: Ray Tracing with POV-Ray: 25 scenes in 25 days (2013)

#35

Post by michal_f » Fri, May 01, 2020, 6:16 PM UTC

BubRoss wrote: post #26

selfsimilar wrote: post #11

Earlier quoted context omitted.

Pragmatically, I think the real issue is editor tooling. Polygons are much simpler to subdivide and edit and are perfect for real-time interaction, at least much better for high-complexity scenes. At render time, though, you need to use a bunch of extra tricks to get the right smoothing - bump/texture mapping, increased subdivision, etc. But some of these other models might actually decrease the scene complexity and…

It isn't just tooling. > At render time, though, you need to use a bunch of extra tricks to get the right smoothing Nurbs or any smooth geometry needs to be subdivided too. You can set levels, max size of polygons, smoothness constraints subdivide based on the pixel size from the camera projection or any combination. In practice this is not a problem for polygons or nurbs. > - bump/texture mapping, This is orthogonal…

3delight also traces SDS and nurbs analitycally. In offline renderers geometry data constitutes to most of memory usage. Texture RAM usage is kept under a few GB by use of page-based cache.

Re: Ray Tracing with POV-Ray: 25 scenes in 25 days (2013)

#36

Post by Macuyiko » Fri, May 01, 2020, 6:19 PM UTC

nikodunk wrote: post #2

I love POV ray so much. It's what originally got me into programming in the late 90s/early 2000s. Found out about it from a PlayStation 1 Magazine.

It holds a special place in my heart as well. In 2002, my parents gave me a book "Multitool Linux" [1] which wasn't a spectacularly well received one, containing a mix of wildly different topics, but this was exactly what I needed as a teen experimenting with Linux for the first time. One of the chapters was about POV-Ray, and I remember being amazed with this newly-discovered canvas. I spend hours looking at images others had created and wondering how they'd pulled it off. I think I never got much further than rendering small animations on my (if I recall correctly) 400Mhz pc. Good times.

(As an aside, I'd completely forgotten the title of the book, although vaguely remembering the cover and time frame. It's so hard to find older stuff using Google when only having some vague descriptions. I found it by remembering that I read a book review years later and after some digging around could locate the review back to https://www.linux.com/news/book-review-multitool-linux/ based on the style of writing, which I remembered. I must have read that book to pieces. The chapter using Wireshark was also amazing to me.)

[1] https://books.google.be/books?id=g0CPF6MEFcUC&printsec=front...

Re: Ray Tracing with POV-Ray: 25 scenes in 25 days (2013)

#37

Post by the_cat_kittles » Fri, May 01, 2020, 6:32 PM UTC

erjiang wrote: post #3

Wow, the state of the art in 3D rendering has changed dramatically. The state of the art in open source 3D rendering has changed even more dramatically. Compare these screenshots from 2013 (although I think POV-Ray was looking pretty dated by then) to renders that come out of Blender's Cycle renderer now. The big change is that everyone has moved to "physically based rendering" that do path-tracing for propagating li…

i dunno, i found it pretty good for making a big 3d datavis- shameless plug: https://somestuffforyoutolookat.ml/pages/hourly_carbon_la.ht...

Re: Ray Tracing with POV-Ray: 25 scenes in 25 days (2013)

#38

Post by packetslave » Fri, May 01, 2020, 6:41 PM UTC

trevortheblack wrote: post #15

If anyone is interested in getting started on Ray Tracing _today_. I recommend Peter Shirley's _Ray Tracing In One Weekend_ Series. https://raytracing.github.io/ (I edited the later editions)

also Jamis Buck's "The Ray Tracer Challenge"

Re: Ray Tracing with POV-Ray: 25 scenes in 25 days (2013)

#39

Post by EvanAnderson » Fri, May 01, 2020, 6:46 PM UTC

POV-Ray was the reason that I wanted a 486 DX back in the mid-90's, and not a puny FPU-less 486 SX like my friends had.

I didn't do much with it, ultimately, but I really enjoyed noodling around w/ POV-Ray. Rendering a bunch of TGA files and then stringing them together into an animated GIF (or was it an FLC?) was a major exercise.

I recall 15 y/o me trying to explain it to the "oldster" who my father purchased the PC from (a guy who was probably in his late 30s). "No-- there's no camera. It's a virtual camera that I place in code for the scene. UGH! You don't understand!" (To be fair, this was a guy who mainly sold PCs and accounting software and wrote code for dBase/Clipper...)

Re: Ray Tracing with POV-Ray: 25 scenes in 25 days (2013)

#40

Post by morsch » Fri, May 01, 2020, 6:54 PM UTC

anthk wrote: post #25

TylerE wrote: post #16

Earlier quoted context omitted.

> It features a lot of effects (radiosity, HDR maps, etc.) which are added on top of its basic functionality Huh? POV-Ray has supported radiosity for literally decades, since sometime around 1995.

Yep, I'm tired of these kids saying PovRay coudn't do shit as if PovRay had in 1997 the same capabilities of an Irix machine from 1987. They couldn't even be more wrong with that. I remember seeing photoreallistic images made with PovRay in 1997 you coudn't even do with a GPU today in real time. Kids today have a lot of ignorance on the 90's technologies, guess why they confuse the 80's and the 90's a lot thanks to t…

> From 30Mhz and 5 1/4 floppies to ~450/600 MHZ a bunch of GB in 1999.

From rare instances of people accessing their local BBS at 9600 Baud to accessing a worldwide communications network as a matter of course, often at broadband speed.

The past 20 years really have been rather dull in comparison.