TITLE: Where your eyes don't go NAME: Henry Bush COUNTRY: UK EMAIL: henry@unforgettable.com WEBPAGE: http://www.soton.ac.uk/~hjsb196/ TOPIC: Worlds within worlds COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT. JPGFILE: whereyou.jpg ZIPFILE: whereyou.zip RENDERER USED: POV-Ray 3.5 Beta 11 for Windows TOOLS USED: Terragen demo (www.planetside.co.uk) for heightfield creation Paintshop Pro 4 for heightfield manipulation and post-rendering brightness adjustment 3DWin (I think it was called) to convert 3DS models to POV format. Winamp to keep me going through those long test renders RENDER TIME: 3 hours 11 minutes 34 seconds (including 1 minute 18 seconds parsing) HARDWARE USED: Athlon 650 running at 682MHz, 512Mb, Windows XP with 3Gb swapfile (385,452kb peak memory usage) IMAGE DESCRIPTION: An image of the top of a lamp in a large rural park. How can we know what goes on where we can't see? This is my first entry in the competition, and I've enjoyed it so much. I was intending not to enter next month due to pressing commitments, but I'm not sure I'll be able to stop myself. IRTC, you've ruined my life and I love you for it! Acknowledgements: to Gilles Tran, for his grass and tree macros. The tree generation macro is a marvel, and the grass wonderful. Gilles, we are forever in your debt! Second, to Howard Day and John Dickson for their A-Wing fighter model (what do you mean you didn't notice it? Go back and look again). And finally to the two anonymous authors of the house and car models, downloaded (free) from the internet as 3DS files. Acknowledgements also to people who helped me by saying what looked crap, and trying to persuade me to change it, despite me desparately trying to stick with things that made my life easy. My housemates, Pete, Jenny and Ben were best at this. Also thanks must go to Steve, who provided the (invisible at this resolution) inscription on the plaque on the bench: "This bench is dedicated to the memory of all the people who have died in mysterious circumstances while sitting on it". DESCRIPTION OF HOW THIS IMAGE WAS CREATED: First of all, a disclaimer. I do not know how I got the idea for this picture. Or what made me think it would be a good idea. But I kinda like the result, and that's all that matters. This image isn't what it should have been. I tried radiosity, but it didn't improve the image much, and increased render times horrifically. A general media fog should have given stunning glows around moon and lamps, but the scale of the scene seemed to be a problem, and all the parameter tweaking in the world wouldn't help. I simulated the glow using spheres with emission media. I wanted to use photon mapping (because it's revolutionary), but I couldn't see any features of my scene which would take advantage of it so I chose to keep it simple. Finally focal blur: again increased render time too much. Now down to business. I had seven cameras to switch between to help me figure what went where during test renders. There are six heightfields (hfs): the main grassy one, three background grassy ones (just so the background isn't scarily flat), the path through the park, and the "small world" (as it shall from hereon in be known) ground. All of them are 513x513 (thanks terragen!). The grass on the main hf is a single patch, 20 x 20 blades, created with Gilles Tran's macro. This patch is then repeated 100 x 100 times (total of 4,000,000 blades), rotated randomly to give less obvious repitition, and placed on the landscape using trace(). I had to write a short piece of code to find the gradient at each point on the heightfield (the trace macro's "normal" function was too localised), and then rotate the grass patch to fit. The grass on the other height fields is a texture. I'm quite proud, because I couldn't tell where the join was, even when it wasn't as dark as in the final scene. The lamps are simple boxes & spheres, and the lightbulb is an area light source which looks_like a sphere. It's also kind of hovering in mid-air, but we'll ignore that. The moon is a parallel light source which looks_like an image mapped box. Oh, and it's only about 100km away, but don't tell anyone. The street lights on the road are spotlights, with bizarre parameters. I just fiddled until they looked right. One of the things that took a surprising amount of time was getting nice illumination of the tree at the back. The leaves on the ground and the water droplets on the lamp are placed randomly: the droplets using simple random numbers, and the fallen leaves using a normalised distribution around a central point (the trees). Sizes of each are normally distributed, rotation of leaves is random. The small world is fairly simple: a heightfield covered by a material_map, with objects placed on it. The A-wing fighter is intended to imply some sort a parallel universe that is more advanced than our own, but it's a bit too subtle. One of the more tricky things was the light on the small world: it had to be coming in from an angle to give nice shadows, but only illuminate the small world (ie, have a circular footprint). I eventually did a bit of (not too complex) maths and projected the parallel light source through a scaled sphere. Worked like a charm. And the title is paying homage to one of my favourite bands, They Might Be Giants, who don't play in the UK often enough!