What’s Alex been reading about?

Alex Evans thinks about lots of awesome techie things, always reading, always learning, always geeking out and making weird and awesome things.

The other day he sent me the text that I now present to you, a collection of thoughts on recent developments in computer graphical hoo-hah. I don’t really understand half of it, being just a lowly writer, but he was insistent that we publish it at once! So here it is, Alex’s mini tech blog, enjoy!

Arnold Render

Arnold render is back! The renderer by Marcos Fajardo, that made those super cute super soft renders back in the 90s and popularised the ‘ambient occlusion’- is back - look here for a blast from the past! It seems that Sony Pictures Imageworks used a new version of Arnold on Monster House and also on Cloudy With a Chance of Meatballs. For graphics geeks, (like Alex) that’s pretty exciting.

After the keynotes at this years HPG (High Performance Graphics) Conference everyone was talking about how ray tracing was the ‘new’ thing. At last! It’s only taken 30 years… And the first beta images of the new Arnold renderer look great


Meanwhile, back into games land – ever since Jon Olick from id (ex Naughty Dog, I believe) gave a talk at Siggraph 2008 about his research on voxels (remember Comanche? Ah, those were the days!) – anyway, yes, voxels on GPU, they seem to be the in thing. This video is quite cool.

More recently, Gigavoxels by Cyril Crassin is a beautiful implementation of a simple idea – volume mip maps stored in a sparse octree – that allows blurring and filtering of voxel scenes. That’s crucial – I hate the blocky look of most voxel renders, which is the equivalent of point sampling of textures – and not intrinsic to voxels at all. Given that my personal graphics manifesto is ‘blur and add noise’ (it solves all problems!) gigavoxels is right up my street. Awesome stuff.

GPU ray marching

Demo land: Iñigo Quílez has been hammering on signed distance fields and GPU ray marching – and has got it down to a fine art. His 4k demos and images (that’s 4k! Tiny! Amazing! Etc!) are second to none. The technique is super simple - but in his artistic hands he creates beautiful images. (shameless plug alert).

I’ve always loved signed distance fields – they mesh neatly with voxels, ray tracing, and blurring-and-adding-noise (see what I did there? :)) – and I gave a talk about it at Siggraph 2006 – “Fast Approximation for Global Illumination on Dynamic Scenes” - which includes a rough / unrefined version of the way that Inigo creates the soft shadows in his images.

That paper also constituted the first time Sackboy was ever seen outside the walls of Mm – and an explanation of how I handle all those little lights in levels - long before LBP was announced! However I put a sphere over his head so that nobody would recognise him. It seems to have worked…

Still with me? Anyone understand that? Good, then you’ll be looking forward to the second part then won’t you? An update from Mister Johnny Hopper about Siggraph 09 - coming soon!


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