TITLE: Minimum NAME: Bertrand Petit COUNTRY: France EMAIL: irtc@phoe.frmug.org WEBPAGE: http://www.bsd-dk.dk/~elrond/ TOPIC: Minimalism COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT. JPGFILE: bpmini.jpg ZIPFILE: bpmini.zip RENDERER USED: Povray v3.6.1 TOOLS USED: emacs; make; FontForge RENDER TIME: 11 hours HARDWARE USED: Pentium IV clocked at 1.7_GHz IMAGE DESCRIPTION: This image is an evolution of a design I used as a unique seasons greetings card. That card was sent to a friend following a discussion we had about how I use the word "minimum" to evaluate some qualities or defects of non-decorative type faces. The greetings card had that word set almost as it is in the present image, it also had a signature. I thought that the adaptation of this paper card to a raytraced rendering would be a perfect match for the minimalism topic. We're dealing here with raytracing so I could not only lay a flat word on a plane, it had to protrude somehow in order to cast shadows. These are deep shadows, that's a deliberate choice at they permit to render the word with a maximum effect on the viewer using only a very limited number of features on the image. I'm quite satisfied of the result. I'm so satisfied that I took the opportunity to try the Zazzle service. You can have a look and by a print at the following address: DESCRIPTION OF HOW THIS IMAGE WAS CREATED: Povray version 3.6 was used to render the image. The word is just a Povray text object using the Bubbleboy type face as geometry source. This type face was designed by Jakob Fischer . Unfortunately that font file missed some of the tables used by Povray to access glyphs. I had to regenerate the font file using FontForge. I also had to make a minor change to the font: the designer did align all curved letters on the baseline. Designing letters this way generates unwanted visual effects: the word appeared unevenly aligned, it looked as if the U letter was shifted upward. Again FontForge was used to tailor the font. The font was specially chosen for that scene from the set of freely available fonts of the DaFont repository. The lighting is very simple: just one spherical area light. I made some tests with a second source to lighten the shadows. That move revealed itself as a bad one as it lessened the effect of the picture even when that second light was configured to cast no shadows. The scene use radiosity even if the influence on the picture is barely visible. That effect is nevertheless important as it creates a lighting difference between the top of the letters and the underlying plane. Without radiosity the top curves appears to blend with the background and that's not desirable. Initially the background plane had just a plain white pigment. When the image was rendered at higher resolutions, the different shades of gray appeared as concentric circles due to the limited number of grays representable using 8-bit numbers. That was not acceptable. However there is an easy trick to overcome this limitation: add some noise. This tricks the eye and the brain to see more shades of gray than there actually is in the image. Several texture tests were made and I settled for a agate-based normal perturbation for both the text and the supporting plane: this looks almost as paper illuminated by a skimming light. Considered the origin of the scene idea I thought that was a bonus. I experienced some difficulties with radiosity settings. Povray lacks a good documentation about the various settings, their effects, and which setting to alter in order to correct common kinds of artifacts. So I had to arbitrarily increase or lower most of the radiosity parameters in order the remove blotches and spots appearing on the supporting place, this partially explains the long rendering. Considering that Povray implements Greg Ward's global illumination algorithm, it would be nice if the Povray documentation team could use radiance documentation and some material in the book Rendering with Radiance by Greg Ward and Ron Shakespeare as a basis for a better documentation. A mapping from Radiance to Povray parameter names would had been enough to me. The area light is another source of intensive computation. I wanted the scene to have absolutely smooth penumbras to contrast the sharpness of the word and the deep shadows between the letters legs. The smoothness of penumbras is directly related to the number of sub-samples used for the area light. Unfortunately the smoothness is also an inversely related to the rendered image size: when penumbras surface raises, one must also raise the number the area light sub-samples to avoid banding effects. The exact rendering time is unknown as I rendered the same scene three times with decreasing resolutions, each one benefiting from the radiosity calculations accumulated by the previous run. The image submitted to the contest was the last being rendered. Another source of imprecision on the rendering time is Povray itself because of a feature I view as a bug: it reports wall clock durations! LocalWords: WEBPAGE FontForge Zazzle Bubbleboy DaFont bpmini txt Here ends the bpmini.txt file.