TITLE: Twisted NAME: Richard Webster COUNTRY: England EMAIL: irtc_mail@yahoo.co.uk WEBPAGE: None TOPIC: Force of Nature COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT. MPGFILE: twisted.mpg ZIPFILE: twisted.zip RENDERER USED: povray 3.5 TOOLS USED: cmpeg CREATION TIME: 14 hours HARDWARE USED: AMD Duron 1.1GHz 128MB ANIMATION DESCRIPTION: While everyone is out storm-chasing, a tornado creates its own logo. VIEWING RECOMMENDATIONS: Tested in Windows Media Player and mpeg_play DESCRIPTION OF HOW THIS ANIMATION WAS CREATED: All frames were rendered at 320x240 with anti-aliasing. All modelling was done in code and the full source is in the zip file. Units are in metres (approximately) with small scale-things larger and large-scale things smaller than they should be. The main elements are as follows: - Scene A ground plane and a sky plane, both with random textures, and white fog for mist. - Building A set of polygons which is included in a CSG object to make it disappear as it is destroyed. - Flag The flag pole is a sphere-sweep with control points allowed to move more the higher they are. The small flapping flag is a small mesh which has a normal pattern with translation linked to the clock. The close-up flag is a large mesh generated from a function which puts waves across the surface with their phase linked to the clock. The flag design is rendered into a separate image map file and uv-mapped onto the flag meshes. - Twister The twister is a funnel-shaped mesh. The texture is a random pattern, similar to the sky, which is given a spherical warp before being applied to the mesh. This means that a translation of the original pattern is seen as a rotation of the warped pattern, with points at different heights rotating at different speeds. Having just one warped pattern created a visible join so the texture uses two warped patterns, each with their joins in a different place, and a further radial pattern is used to blend the two warped patterns together so their joins are never visible. There is probably a simpler way of doing this. The formation and the dispersal of the twister is done by having a `density' parameter which controls the value in the colour map at which the colour switches from solid to clear. - Air Debris Each piece of debris in the air follows a path in cylindrical coordinates and each is given a different start time. - Furniture Simple larger-than-life block models. - Ground Debris A second version of the flag design, without the text, is used to position the debris in the final scene. The design is used as an image map whose pigment is evaluated to give the test for placing each object.