TITLE: Spiders! NAME: Andrew Spencer COUNTRY: United States of America EMAIL: spencere@geocities.com WEBPAGE: http://fly.to/spencer TOPIC: Nature COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT JPGFILE: spiders.jpg ZIPFILE: spiders.zip RENDERER USED: POV-Ray for Windows v.3.02 TOOLS USED: Paint Shop Pro 4 to create image maps, decrease brightness, add signature, and convert to jpg. RENDER TIME: 1d 07h 13m 38s HARDWARE USED: Pentium II 300, 128MB SDRAM IMAGE DESCRIPTION: The setting is a sparesly wooded oak forest a short walk from a lake in Northern New Jersey in early Spring. A spider has found the perfect spot for a web: two thin trees growing very close to each other at the base. Its web is now finished, and upon the center sits the tiny creature, waiting for food as the evening begins. Suddenly, an intruder slowly creeps up the web! The spider turns and stares. The approaching threat is another spider longing for the perfect habitat to steal. The mother spider waits at the center of her web as the attacker continues its encroachment. As a warning she plucks at her web as she does when an insect lights upon her strings. The intruder hangs on persistantly. DESCRIPTION OF HOW THIS IMAGE WAS CREATED: This entire image was created with pov. Aside from PSP for the image maps and heightfields (all three of them), no external programs were used, no pov utilities, no plug-ins or patches or modelers. This was just a little goal of my own. Inspiration- What I described in the image description is, in fact, quite true. I had decided weeks before I knew the topic that this would be my first submission, and around the same time I had noticed three or four spiders had made a home out of the window directly beside my computer. Since they had no apparent way of getting into my house, I saw no reason to kill them. Instead, I delighted in watching their daily lives. The spiders would come in the early evening, around 5:00PM. I watched as gnats and small moths found themselves helplessly trapped and unable to move stuck to the web and witnessed the spiders' ruthless methods of food preparation. By morning they always had disappeared again until just before sunset. One night I saw something I found to be especially intriguing. It appeared as though one spider was threatening another. The largest spider sat passively in the center of her web until another, only slightly smaller, spider began encroaching upon her. Once, the intruding even ignored the warning of plucking and continued moving in, only to be chased out again. Or maybe they were mating. I really don't know. I now have many videos (taken with my digital cam) on my computer of the spider catching, devouring, and preserving her prey. The spider eggs have since hatched, leaving me with dozens of tiny black dots with legs (some of which have built their own little webs in my window). The mother, I'm afraid to say, has since died (her legs are still in my window and I haven't a clue what happened to the body). The location of the image, as described in the image description, is also very real. You see my house is on the lake only a short walk from a sparesly wooded oak forest. I walked into the forest to find the location until I found a spider web low to the ground in between two thin trees growing very close to each other at the base. The Spiders- This was the easiest part of the image. The spider is a few basic primitives stuck together to form the basic shape of a spider. The colors and patterns on the spider, as well as the orientation of the legs and size of the spider body parts, are taken from drawings made of none other than the spiders in my window. The spiders legs are set up uniformly to give it the look of rigidity it would have when ready to fight and also because it made it so much easier. The second spider is the same as the first only a bit smaller with the legs moved around so they would land on the web's rings. The Web- Of all aspects of the image, the piece of which I am most proud is the web, although I do have to give much of the credit to my father. Before beginning this image I had no idea whatsoever how to use RAND or WHILE and had no clue about what sin and cos even stood for, let alone what they meant. I first set up the long strands, or spokes, of the web. Eight of the spokes are specifically positioned to intersect the feet of the large spider. The other seventeen were placed where I thought they looked best. That part was easy. Then I went to my father to learn how I could place cylinders spiraling outward to get the look of a web. He explained cos and sin to me and showed how I could use them to find the ends of the cylinders. So my original intention was to find all these points by calculator, write them on paper, then transfer them by hand to pov. As I was impatiently going about this terribly boring business, it occured to me that I had seen pov to calculations such as these on its own somewhere before. I still don't remember where I saw this, but I am extremely glad I did. I thought to look through the pov docs. After doing a search for "cos" I found that pov could do what I was doing and much more. Some weeks before I had written an Email to Sonya Roberts inquiring as to where I could learn to use RAND and WHILE and such and she sent me to "The Rendering Times." There I read a summary of how to use these features, didn't understand a word of it, and shrugged it off to be learned at a more convenient time when I had nothing better to do. However, it occured to me that this could be the perfect opportunity to learn, so once again I turned to a more expirienced person for help. My father read the POVAbilities editorial and then explained exactly how I could use these options to make my spider web not only be generated completely by pov, but also use these new-found commands to make the web more naturally imperfect. The results surpassed my expectations. The Leaves- If you are subscribed to the IRTC Mailing List, you may recall I requested how a single leaf might be modeled. After reading a few responses it occured to me to use the image from Sonya's Trees.inc plugin to create a heightfield. This rendered a satisfying result. I then textured the leaf with random values of red and green (it doesn't look very good up close, but they are pretty small and out of focus, so that doesn't really matter). I was originally putting quite a few leaves in and getting oddly sparse results. The image wouldn't look satisfactory until I had placed a total of 3,000 leaves on the ground and 2,000 and the air (for shadow). This made the image take FOREVER to render. Those of you on the IRTC List may recall my plea for help because my computer wouldn't render it fast enough. I did get a few with more powerful computers to help me out, but while they were rendering, I looked at the code for a more fast and efficient means of placing the leaves. Before long I realized I had made a simple mistake. The leaves had all been translated randomly and then rotated randomly. Apparently I had forgotten that the rotate must always come before the translate... Upon fixing this, I found 200 leaves on the ground sufficed. I Emailed my thanks and apologies to those who were willing to help. The Rest- The camera angle was determined by trial and error, at first I had the camera up very close. That however, gave it the look of giant spiders on a giant web in a giant forest, so in order to preserve the scale, I zoomed out. Because of this, I lost many of the spiders' details, but that's life. Use of the focul blur was planned from the beginning. There are three light sources: the Sun which is waaaay up in the sky (just like the real sun :), and a very dim white light placed on either side of the web to create an ambient look without losing the surface normals on the trees. The tree bark is a hexagonal pattern (what you can't tell?) of three surface normals and three pigments done by eye. This took a little while to get right, but it looks great now doesn't it? The ground (below the leaves) is the same texture as the tree bark, but with a -0.6 ambient value to make it darker. Lastly, the trees are just cylinders sticking out of the ground. I would like to give a special thanks to those who were willing to help me out with rendering the old final copy (the one with 5,000 leaves), especially Andrew W. Cherry and Jonas Klereborn for tying up their computers for two days. I really appreciate the effort.