March 2019

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Time to clear the link collection before GDC/GTC – download some web pages for the plane ride.

OK, even I’m getting a bit tired of writing about Ray Tracing Gems (not to mention Real-Time Rendering) goings ons. But, a few things:

  • The code repo for Ray Tracing Gems is now up! Some more code will be added and updated later, after the GDC/GTC rush.
  • At GDC Naty Hoffman, Angelo Pesce, and I will sign copies of Real-Time Rendering on Wednesday, 3-4 PM, at the CRC booth, P1867, located near the Connect Lounge. If you’re around (and even if you already have a copy or never want one because GPUs are a fad), come by and say “hi.”
  • Authors of Ray Tracing Gems will sign the book right after, 4-5 PM, in the alcove west of Room 201 South Hall (two floors up). It looks like at least 17 authors will be at GDC, but all may not be able to attend. I’ll be giving a rap-free fast-forward talk after, in Room 205. Map below.
  • GTC: book talk Thursday 2-3 PM room 230B (Concourse Level), book signing after at the GTC bookseller 3-4 PM.
  • The only physical copies of Ray Tracing Gems available until May will be sold at GDC and GTC, nowhere else. So buy them all and resell on EBay. No, don’t do that.

Really, all this info except the Real-Time Rendering signing is covered on

Book signing (in yellow) map for GDC, right next to the restrooms – classy 🙂


I haven’t done one of these for awhile – too busy with The Book (not That Book; the Other Book). Here’s a collection of stuff I’ve noticed the past few weeks.

  • GDC: hey, there’s a Shadertoy meetup. Me, I’ve been to GDC only once before, back in 2001, and look forward to going this year. Help me out: What should I know about and not miss?
  • If you’re in the Boston or London area in March (the 31st and 16th, respectively), go to BAHFest. I went last year for the first time, and it was pretty great. Here’s a winner from last year, how cats are behind crypto-currency fever.
  • Youtube recommended I watch this video, and they were right! Path tracing explained fairly well, in a wonderful hokey 50’s style. Andrew Glassner pointed out there’s another in a similar style, on snow simulation.
  • Clickbaity title, but I liked this article for its rundown of color blindness and a possible cure.
  • Also in Wired: Lena/Lenna is an iconic image, a symbol of objectification, and a point of pride to Lena herself. The world’s a fascinating place, which is one of the reasons I live here instead of on Mars.
  • Just so there’s some actual chewy technical content in this post, see this article on mesh simplification. It has a generally-applicable idea: you often don’t need an exact sort, just a rough one, e.g., for depths or sizes of objects. For that, a single-pass radix sort might be just the thing. BTW, there are a surprising number of odd videos on sorting: Radix sort (and different group, different song); bubble sort – I’m a sucker for Balkan music; and this 15-sorts one – no dancing, and sounds like a set of 8-bit game sounds run amok, but still interesting if you know the algorithms. I hadn’t heard of the cocktail shaker sort, and sadly the bogo sort is not played to completion…
  • Improved Kill/death ratio as a selling point. Admirably, they attempt to control for skill level, based on number of hours played as a proxy. Surprising conclusion: “the higher the skill level, the more that players are attuned to the game and can benefit from differences in hardware.” Also, 144+ FPS seems to be the current frame rate to aim for. Yes, I work for NVIDIA now, but I found it interesting and believable. If you’re in sales, you’d like the opposite to be true, “just buy new hardware and you casual players – the vast majority – will benefit the most.” (Thanks to Pete Shirley for pointing this one out.)

Repeat that title three times, then “and I feel fine.” This R.E.M. song has been going through my mind much of the week, as the Ray Tracing Gems book was released last Saturday as a free PDF. With Open Access, the publisher agreed to put the book up for free, even before the physical book was available. Apress has 27 other Open Access titles free to download, so they’re somewhat used to the idea.

The bragging number is that the official Ray Tracing Gems PDF has been downloaded 102K times as of today. I suspect there are a lot of pack rats out there who will download any book that’s free, or someone’s trying to make Tomas and me feel good by setting up an auto-download bot farm (if so, thanks, good job!).

But wait, there’s more. Stephen Hill spotted some typos in the preview copy and sent them on to me Saturday. Monday I made an unofficial PDF for distribution, identical to the official PDF but with his and other errata fixed. Doing so is fine under the license, which allows reasonable changes that are properly noted. The publisher and I worked on the wording on the front page to clearly label this version as unofficial, then I released it on Tuesday. It’s of course the one I recommend grabbing. Being more “hidden,” this one’s been downloaded a more believable 499 times as of last night.

“Supplies are limited” is my favorite ridiculous marketing phrase, always true since there’s a large but finite amount of material in the universe. For GDC and GTC, it’s actually true. The publisher is rush printing and shipping a few hundred copies for these conferences, and they should arrive at onsite booksellers and to NVIDIA next week, fingers crossed, knock wood, rub lucky rabbit’s foot. The hardcover book will not be available for online purchase until mid to late May, though on slightly-higher quality paper (coated glossy vs. coated matte; I believe “coated matte” is what the GPU Gems series used).

Me, I like having both the physical and the electronic forms: electronic is great for searching and for travel, physical is nicer to read (at least for me), use stickies on, add notes in the margins, and for getting signed. Speaking of which, see our page for authors’ signings and talks at the conferences.

So, this is all an odd sequence: NVIDIA released free preprints of the book during February, as did EA; the publisher released the PDF for free in March; I (or anyone) can then make a slightly improved version for distribution; the physical book will be available at conferences in 10 days but not for online purchase until May. Releasing preprints of a whole book, fixing errors in the released version – this is not something we’re used to. Personally, I know I’ve had any number of emails along the way where we each reassure the other, “no, it’s OK, this is how it works under Open Access.”