TITLE: Ghost Light NAME: Bill Pragnell COUNTRY: UK EMAIL: billpragnell@hotmail.com WEBPAGE: http://www.infradead.org/~wmp/ TOPIC: Absence COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT. JPGFILE: wp_ghost.jpg ZIPFILE: wp_ghost.zip RENDERER USED: MegaPOV 1.21 TOOLS USED: DAZ Studio for figure pose Blender for figure fine-tuning PoseRay for figure conversion InkScape for lathe splines GIMP for image map preparation RENDER TIME: 4 hours for first radiosity pass, 8 hours for final render HARDWARE USED: MacBook 1.8GHz 512MB RAM IMAGE DESCRIPTION: Is a ghost a presence? Or an absence? Even if it is a presence, it must signify somebody's absence. Perhaps if I were absent through death, but sill present in some form, I would have a brief look at my absence. Perhaps I wouldn't. Perhaps I would remain absent. This young woman, however, is clearly inspecting her absence with great interest... DESCRIPTION OF HOW THIS IMAGE WAS CREATED: My starting point for this image is fairly unique; I typed the topic, 'Absence', into Google Images, and one of the first hits was a picture of an empty armchair. The rest followed from there... :) The chair, table, sideboard, shelves, walls, fireplace, fire grate, ashtray, lamp, mirror-ball and picture frames were all built using normal CSG techniques (with rounded edges where possible). I wrote a macro to build picture frames given an arbitrary cross-section object. The pictures are adapted from my own photographs to avoid permission issues - the panorama is a Scottish loch and the sepia print is Venice, Italy (both pictures I took whilst on holiday earlier this year). The small picture on the mantelpiece is actually Aiko herself, screen-grabbed from the DAZ Studio viewport. The bottles, vases and wineglass are all lathes employing bezier splines created using the excellent InkScape. The bottle labels are image_maps of random wine labels downloaded with the help of Google Images (I can't remember the sources, so I can't credit them... but you can't really see them well enough to tell what they are, anyway). The books on the shelves are of two types, generated using my own book macro. The paperbacks have randomly generated titles and authors (taken from text files of names and likely title vocabulary), with semi-random colours. The hardbacks are much more regular. The ghost is my crowning achievement of this image, and is something I'm extremely proud of. I took the standard Aiko 3 model and posed her in Daz Studio. Then I ran her through PoseRay to remove all unnecessary mesh components (tongue, teeth etc), not to mention the zero-thickness add-ons (eyelashes, pubic hair etc). Next, I imported the resulting wavefront object into Blender, homogenised the mesh, and properly closed the remaining open sections (mouth and eye sockets). Then I exported two versions of the resulting mesh to POV-Ray: one unchanged, and one very slightly shrunk along its normals. Putting a hollow version of the former around an opaque version of the latter and filling it with emissive media provided the glowing 'skin' effect. The hair was exported from DAZ Studio as a separate object, and extruded in Blender to produce a closed volume, which was then exported to POV-Ray and also filled with media. There are no light sources in this scene; it is lit entirely using radiosity. The lighting in general has been a real headache, and I'm not really satisfied with it at all. I originally used area_lights inside the ghost, but the size and proximity to some of the objects caused strange shadow problems... and the render time was extortionate. In the end I spent over two weeks playing with radiosity techniques, and I've basically run out of time. The submitted image is the best I can do, and it's far from perfect: it looks ok, but on high-gamma displays (or after correction) the darker areas (under the sideboard, around the shelves) exhibit some really prominent artifacts. Even the brightly lit areas show a fair amount of splotchiness, although this isn't so bad due to the obviously irregular nature of the light source... It's difficult to know how to improve it further, because the radiosity settings are already really silly - count is maxed out for both passes, error_bound is 0.02, minimum_reuse is miniscule and the first pass had to be performed at full resolution in order to catch all the shadowed areas. I think the way forward is to combine a small area_light with the radiosity and employ a much higher level of smoothing in the final pass. This will take a very long time to render, and the results will eventually be posted on my website (see above). A note on the zip file: I've tried to supply everything needed to reproduce the picture, including the ghost geometry include files produced by PoseRay (these are very large). I haven't included the BillMacros.inc file, but the only macro needed from this is the RoundedBox() macro, other versions of which can be found elsewhere. Or just replace it with a normal Cube. Obviously both radiosity passes will also need to be performed.