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John Valentine

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Here's a prototype GPU implementation of the reflective ellipsoid. I've limited it here to 512 x 360 @15fps with 512 bounces, until I can better schedule available GPU resources. I've had it running 60fps at this resolution, or 1Kx1K @15fps.

I've automated all the animation, and hope to add a UI to control that, along with manual camera control, and graphics tweaks.

Source code should be readable, hopefully.

http://johnvalentine.co.uk/index.php?art=ray2
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+John Baez  The noise/scintillation is due to 'single precision' computing of up to 512 consecutive reflections for each ray; an early error is doubled* for each reflection. The ray-traced version benefited from anti-aliasing, double precision, and a better lighting model.

I could ask the compiler for double precision, but that might not work for most users. When I get around to making a free camera for it, I also want to allow the selection of precision.

*Each result has error ±2^-22, so I expect the 'last ray angle' error distribution to resemble a low-variance normal curve, so it should never really achieve the maximum possible = 2^(511-22)
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CO2 emissions caused by advertising - part 2

I rarely offer comment on Slashdot, as it can be an arena for pedants to mercilessly hack at well-meaning posts. I said "rarely", so there's inevitably going to be at least one where I did offer comment. To my relief, it was kindly received, and now sits at the top, proudly bearing the highest capped score of 5. But that's not why I'm writing about it now.

The post was "iOS 9 To Have Ad Blocking Capabilities", but the point I want to make here is different from the point I made on Slashdot.

On 29 Apr, I lamented here that lots of energy is wasted serving animated ads. I would be very pleased, from an ecological viewpoint, if processor-intensive ads were banished. Your device would then suck less juice from the wall, or last longer on a charge, and (a personal favourite of mine, but off-topic here) you might be less distracted from the content you came for.

I'd like to know how much electricity is spent creating, delivering and consuming advertising content.

I say with a tinge of regret, that any indiscriminate advertising ban would make life very difficult for those websites that depend on advertising revenues for their existence. I have this conflict when I run an AdBlock variant for almost all my web browsing, because I find the ads too distracting.

Ideally, in terms of my immediate experience consuming media, I wish advertising didn't exist. But we all know it's a lot more complicated than that, and we allow our personal boundaries to be shifted in order to get to the good stuff.

J.
_ _ _

Finally, my Slashdot comment started with this: "This makes sense in the Apple ecosystem. It speeds up web browsing and streamlines the experience, if ads are blocked at browser or OS level"
... It's a pity then that I forgot to press the energy-waste argument at the same time! Though I imagine I wouldn't have earned a high score, and the resulting tree of replies might have scared me off. Maybe I'll go back...?
An anonymous reader writes: iOS 9 will reportedly carry ad blocking capabilities for it's Safari browser when it is released later this year. The feature wasn't rolled out with the usual fanfare one might expect, and flew under the radar. ZDNet reports: "It's not immediately clear why the new ad-blo...
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Diagram tools/automation

Diagrams are always more useful than a long, confusing paragraph of "who said what to whom"! This one is 'hand-drawn' in an Illustrator app, but I'm working on a JavaScript/HTML generator for these, which might include a solver, which would make both static and interactive diagrams quicker to make.

This diagram is of a decay using a deterministic vacuum. I used it in a 2013 paper showing a foundation mechanism that seems to generate the standard physics stuff. This week, I'm writing a piece with a central theme of vacuum, and how we can show conventional fields as statistics of uncollapsed matter flux, and pull out a tonne of detail from interactions.

I don't think I'll soon have automated diagrams with this level of annotation, but at least I'll be able to get that first layer from a few lines of data.

I'm also working these into the existing supporting web pages, which are due a little love, like http://johnvalentine.co.uk/po8.php?art=constitution
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+Refurio Anachro, you mentioned being able to shade according to the angle of incidence to the marble. Try this:

#declare pig1 = pigment {color White*1.0}
#declare pig2 = pigment {color Blue *1.0}
#declare pig3 = pigment {color Red  *1.0}

#declare M_InnerBall2 =
material {
   texture {
      pigment {
        aoi
        pigment_map {
             [0.00 pig3] 
             [0.50 pig3] 
             [0.55 pig3] 
             [0.551 pig1] 
             [0.65 pig1] 
             [0.70 pig2] 
             [1.00 pig2] 
        }
      }
      finish { diffuse 0.0 ambient 1.0 }
   }                           
}  

This example image is a bit more zoomed in (90° rather than 165° FOV)
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I'll do some reading on that soon, as I want to understand it (and it seems counter to my expectations).
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+John Baez  +Refurio Anachro  — As per previous comment, here's the colour image from inside the spheroid, with the white ball lit from three directions with soft red, green, and blue lights. It adds so much to the image, because the colour is determined by the view on the inner sphere. The render is using an ultra-wide-angle camera, and the outer parts of the image are dominated by the light that illuminates the part of the inner sphere that touches the reflective sphere. 4k × 4k image.
#RayTrace   #EndlessReflections  
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I've been wanting to do this for a very long time: categorise my stories. Sometimes the simplest answers are best... My website already runs a search (in article keywords) if a requested article is not found. I already have 'action' navigation buttons. Combining the two gives me what looks like articles tagged with categories, here:
> http://johnvalentine.co.uk/fiction.php
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Paperweight! It's an experimental arty thing. It contains a rainbow ring of glowing coloured blobs. The ring of grey blobs allow themselves to be lit by those blobs (but I think they get in the way and reduce the impact of the image).

If you look 'into' it, can you work out the reflections?

It's not as good as I wanted, but lets me think about the next try. Next, I want to get interesting mathsy shapes and colour patterns in there.

I did something similar a couple of months ago. This time I'm going for a less abstract, and more realistic view. This one cheats a little, by increasing the amount of light that internally reflects, so that you get more reflections.

Lastly, once you see the face, you can't 'unsee' it :o)
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Based on how far I got last time with a hardware solution (GPU rendering), I think I know what to do next time. I've since found an ellipsoid solver, for which I need to flip normals to do it from the inside.
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Access to Science: against for-profit business in science publication

I thought it might be worth rolling out this blog from 2012. It is perhaps idealist, but the weight of evidence and concern is gaining momentum in this direction.

http://johnvalentine.co.uk/po8.php?art=access_to_science

Summary
1. For-profit companies are exploiting academic publication.
Reduce the artificial gateways and paywalls, at both submission and consumption.
2. Reform must avoid further exploitation.
3. Remove for-profit business from the academic publication supply chain.
4. Invest in concessions, making publication a loss-making venture, while enriching academia in other ways.
5. Change needs the momentum of a culture shift, and our refusal to accept the creeping terms of for-profit business.

See also: "Scholarly Publishing" - https://plus.google.com/collection/wXB5Y
Summary. For-profit companies are exploiting academic publication. Reduce the artificial gateways and paywalls, at both submission and consumption. Reform must avoid further exploitation. Remove for-profit business from the academic supply chain. Invest in concessions, making publication a ...
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A long reach, that point 3, I'm afraid, since that's the biggest sticking point for commercial publishers!
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How much of the CO2 in the atmosphere is caused by auto--playing media, like Flash animations, GIFs, and ads?

There's an emerging trend for constantly-animating HTML/JavaScript. which can only add to the problem.

Should there be more awareness about this?
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Here's a proof-of-concept GPU demo in WebGL/JS/HTML5. It renders 256-deep reflections, 512 × 512 pixels, 60 fps, and uses about 25% of my GPU. Now I just need to formulate a function that correctly reflects an ellipsoid (for this image, I just mangled a sphere function to give an interesting but incorrect pattern).

http://johnvalentine.co.uk/index.php?art=ray1 
(work-in-progress; I'm new to this!)
+Refurio Anachro +John Baez 
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+John Baez Here's my response to Endless Reflections: my Endless Refractions (glass sphere, 10% stretch, IOR 1.5, 255 depth, Fresnel tweaked, gamma-corrected). I think I haven't quite hit the best viewpoint. I'll try a few more, and I know that a bit of colour will make these look great.
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It's the same ball! but it's emissive, hence the spot of light on the floor.
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I just wasted about an hour trying to debug why the headings were in heavier type than I was expecting.

tl;dr: It's a Chrome bug; they work fine in other browsers*

The image here is from the font's own web page. Chrome renders the 300 weight of Open Sans as if it were 400.

*Well, Firefox renders the 600-weight as Times on the font's own demo page.

#OpenSans   #Chrome   #Bug   #OpenSans300  
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^ that's not correct. I was using a different computer.

The real cause of the problem was that I had Open Sans installed on my system, so it was conflicting with the web font.

Hat-tip to http://www.reddit.com/r/css/comments/2pdpxr/anyone_else_having_issues_with_google_webfonts/
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Sphere in Mirrored Spheroid | Visual Insight
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A spheroid is an ellipsoid with an axis of rotational symmetry. This image created by Refurio Anachro shows a sphere inside a mirrored spher

YouTube - Zenith gameplay demo 2 (moderate game)
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Create AccountSign In. Home. BrowseFilmsUpload. Hey there, this is not a commercial interruption. You're using an outdated browser, whic

The Sentinel is an Extraordinary Computer Game (1986) - STUCK ON AMBER
stuck-on-amber.typepad.com

Rarely a digital game reached that level of formal beauty. Brilliant use of design constraints, tense atmosphere, and 10,000 levels to explo