* * * * * * * * * * * * * * Capture the Night II * * Dan Connelly * * djconnel@flash.net * * * * * * * * * * * * * * EMAIL: djconnel@flash.net NAME: Dan Connelly TOPIC: Night COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT. TITLE: Capture the Night COUNTRY: United States WEBPAGE: http://www.flash.net/~djconnel/ RENDERER USED: POVRay Windows 3.0, Vue d'Esprit (stars) TOOLS USED: Paint Shop Pro 5.3 Beta (JPG, signature) RENDER TIME: 20 hours HARDWARE USED: PII 266 MHz, 64 MB memory IMAGE DESCRIPTION:see below DESCRIPTION OF HOW THIS IMAGE WAS CREATED: see below theme ===== This image is a play on symbols of the night. The Moon, stars, lightning, darkness, and mystery are all fundamental aspects of the night, and each is featured here. The Moon, held captive by an electrical matrix supported by issuing a cloud of variants on the Clarkian monoliths, is the center of the scene. Yet the discharges which restrain it bathe it in total illumination, depriving it of darkness.... of a night of its own. The stars in the midnight sky provide a backdrop for the scene. The Earth shines brightly among them, taking the place normally occupied by the Moon in nighttime images. The lightning, a matrix of electrical discharges, holds the Moon in in a glowing umbra. Darkness... and mystery, also dominate the scene. But what is the scene? What is the structure? Clearly it is some sort of synthetic pool... the water indicative of some sort of mass-mediated force. The discharges imply an atmosphere, while the waves imply a thermodynamic driving force. Clearly it's extraterrestrial, as Terra rests smugly in the starlit sky. The roof cage increases the Moon's isolation from the natural night. And then there are the monoliths. Clark's "2010" objects were deeply tied to Night. Totally black, they conspired to turn Jupiter into a second sun, stealing the night from the Earth. Thus their inclusion here is appropriate, although in a crystalline, translucent form. But the water? Perhaps one could cite water's recently confirmed presence in Lunar soil. But really that would be a stretch. The real reason for its inclusion is its simple effect. What provides a better support for a starry sky than a body of water? Water itself is virtually a symbol of the night, and raytracers certainly do it justice. files ------ main2.pov : main scene source watermap.pov : water heightmap generator spark#.inc : spark object definition, where # is from 1 to 12 earth_texture.png : image map for earth (not included) moon_texture.tga : image map for moon (not included) stars3.gif : the sky image map (not included) history ------- I first rendered this image using Bryce 3d with mixed results. I regenerated a version using Ray Dream Studio, which proved better, but the graphical user interface gets in the way of images of this nature. I even tried a simplified version on Crystal Graphics Impact Pro demo version as an experiment. But by far the best tool for the job proved to be POV-Ray (my first project with this tool), which is the one I am using for this contest. The procedural, text-based input format allows precise specification of layout and substantial flexibility in making modifications. It is also perhaps the fastest renderer of the bunch. modeling -------- First done was the star field. I did this using the cloud generator in Vue d'Esprit (they are very small clouds...) and used the result as a sky-sphere image map for the POV run. Vue d'Esprit is an excellent terrain generator and tracer and a lot of fun to use. The Earth and Moon were image mapped spheres using brightened versions of images downloaded from the NASA web site. The Earth is illuminated by a spotlight placed well below the scene, placed in the background. Actually, this could have been more effectively rendered by just using a photograph of a crescent Earth. However, in the raytracing spirit, I let POV work a little. A weak infinite point source was placed at the Earth position, to simulate the subtle effect of the Earthlight on the scene. The "stadium" was rendered as 13 cylinders -- 12 pillars and two to create the wall which fills in the space between them, which is the difference between two concentric cylinders. The cage was generated using a "sphere" of 33 toroids, 11 aligned along each of the three principle cartesian axes, clipped by an infinite plane. Interesting, the cage more than tripled rendering time. The water was generated with 12 "wave" functions, each the superposition of 3 ripple generators located near the center of the pillars. This was done to approximate a normal mode of the pool. While applying this function to a normal field on a planar water was okay, far better results were achieved by using a height field generated with the separate file, "watermap.pov". The map file was generated in 512x512 resolution without antialiasing. The 3 rings of monoliths were generated using translucent, refractive, semi-reflective boxes. They are assigned a diamond-like refractive index to indicate a crystalline structure. The sparks were generated using the Stomp Spark Generator from the Pile POV web site. Each consists of 128 cylinders. 12 sparks were generated... they are shared among the 28 monoliths in cyclic fashion. Each spark placement was given a random rotation to increase variety. To simulate the lighting the sparks gives to the scene, a point light source was placed at the expected midpoint of each spark. The color was moved towards blue-violet from the default white. The Moon-glow was applies as a straightforward spherical halo. It was kept simple to avoid overburdening the scene with detail. rendering --------- Without the cage superstructure, the scene could be rendered nicely in 1.5 hours or so. However, the cage introduced substantial opportunity for aliasing effects. Due to the small diameter of the tubes, it was textured without reflectivity (using metallic specularity instead). Even so, to avoid clear artifacts in the reflections of the cage off the cylindrical faces and the waves, adaptive oversampling was used (no jitter, threshold 0.1, maximum depth 3), increasing the rendering time to 20 hours. Perhaps even more oversampling could be used -- if there was a way to locally increase the oversampling for rays which hit the cylinders, I would have employed it. Note I rendered the image to look good on my system, using an "assumed gamma" of 1.8. On some systems they may appear too dark -- if you are using a UNIX workstation you may prefer to apply a positive gamma to the image before viewing. post-production --------------- Paint Shop Pro 5.30 Beta was used for JPG conversion and signature application. scientific precision -------------------- No attempt to follow Maxwellian or Newtonian physics was made here... the electrical discharges, glowing Umbra, and planet-scale was meant for visual effect and interest rather than representing current understanding. conclusion ---------- Overall, the scene is quite simple, yet the result had a pleasantly surprising richness. I invite inspection of the source code, which I have attempted to make flexible and readable. I have not included the image maps or the Vue d'Esprit source, as these would take a disproportionate fraction of the disk space. Dan Connelly djconnel@flash.net http://www.flash.net/~djconnel/