TITLE: Perspectives
NAME: John Guthkelch (Doctor John)
COUNTRY: U.K.
EMAIL: jguthkelch@netscape.net
TOPIC: Frozen Moment
COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT.
JPGFILE: jgperspe.jpg
ZIPFILE: jgperspe.zip
RENDERER USED:
Povray 3.5
TOOLS USED:
gvim, The Gimp, F. Dispot's gearmess program and imagination
RENDER TIME:
10 hours 0 minutes 9.0 seconds
HARDWARE USED:
Home-brewed P-166 with 32 meg RAM and two clunky ST3660A (520
meg) HDDs! I'm still also using my seven-year-old 15" monitor - gamma in the
range of 3.5 - 3.7 (or thereabouts)
IMAGE DESCRIPTION:
thinks Frozen Moment? Frozen Moment?? A snapshot of a
moment in time? A frozen moment of fear? A cold and windswept landscape?
*goes for beer and chat with friends* A moment in time? It
depends on your viewpoint; your perspective, if you like. Are you looking
from a human viewpoint, an atomic viewpoint, planetary, stellar...?
*return from beer* *start coding*
As stated above, it depends on your perspective. So I've brought together
four different timescales. Stellar, Planetary, Human (the clockworks) and
Atomic (an idealised atomic lattice).
Note the artistic joke - using a field camera to distort perspectives :-)
DESCRIPTION OF HOW THIS IMAGE WAS CREATED:
The starfield and the M-type
planet are basic POVRay constructs. No trickery involved, tho' it's probably
worth noting that I raised the cloud sphere above the planet sphere to give
a better impression of dimensionality.
The clockworks lean heavily on Marc Schimmler's gear-wrapper macros and F.
Dispot's gearmess algorithm. Without both of these, I would still be trying
to work out the complex spatial maths to produce a gearset that at least
looks like it has a fighting chance of working. Many thanks to both of them.
The atomic lattice is again a basic POVRay construct, an infinity box
produced by making a box with zero colour and total transmission with an
interior texture of an almost perfect mirror. The only problem I had with
this was in adjusting the verticals, which led me to produce my FieldCam
macro. This is at the bottom of this file if you don't want to have to unzip
my source code.
The story of the final render deserves a separate chapter all to itself. Put
it this way: It's 02:55 on 31-12-2002, it's raining, I'm on line 63 of 900
for the sixth time and I've got a full mug of coffee. Hit it, Jake!
Full code (apart from my starfield.inc) is in jgperspe.zip - jgperspe.pov
has Unix line-ends, jgperspedos.pov has DOS line-ends.
****************************************************************************
Statistics for jgperspe.pov, Resolution 1200 x 900
----------------------------------------------------------------------------
Pixels: 1081200 Samples: 2602272 Smpls/Pxl: 2.41
Rays: 6191687 Saved: 0 Max Level: 15/15
----------------------------------------------------------------------------
Ray->Shape Intersection Tests Succeeded Percentage
----------------------------------------------------------------------------
Box 225876615 26160777 11.58
Cone/Cylinder 696554616 343287442 49.28
CSG Intersection 231386368 22349261 9.66
CSG Merge 118379550 26730398 22.58
CSG Union 191400570 14287725 7.46
Plane 526875542 373157404 70.82
Prism 5294181 4685875 88.51
Prism Bound 132354525 93606878 70.72
Sphere 27178738 12035580 44.28
Torus 80345652 3349548 4.17
Torus Bound 80345652 4170318 5.19
Triangle 28064 12613 44.94
Bounding Object 290635681 37532612 12.91
Bounding Box 1712664895 551319679 32.19
----------------------------------------------------------------------------
Roots tested: 8393915 eliminated: 475466
Calls to Noise: 5336877 Calls to DNoise: 34494863
----------------------------------------------------------------------------
Shadow Ray Tests: 84544162 Succeeded: 9180925
Reflected Rays: 2798354
Transmitted Rays: 791061
----------------------------------------------------------------------------
Smallest Alloc: 10 bytes Largest: 24028
Peak memory used: 3957194 bytes
----------------------------------------------------------------------------
Time For Parse: 0 hours 0 minutes 6.0 seconds (6 seconds)
Time For Trace: 11 hours 0 minutes 58.0 seconds (39657 seconds)
Total Time: 11 hours 1 minutes 3.0 seconds (39663 seconds)
****************************************************************************
// A macro that simulates a true architectural field camera. No longer do you
// have to ensure that the camera location/look_at vector is parallel to the
// XY or YZ planes before shearing the camera to get parallel verticals.
// Don't forget to switch off Vista Buffers using -uv on the command line
// before attempting to render your image.
#macro FieldCam (CP, CL)
#local CD=CL-CP;
#local HypoXZ=sqrt(pow(CD.x, 2)+pow(CD.z, 2));
#local CosThetaX=CD.x/HypoXZ;
#local CosThetaZ=CD.z/HypoXZ;
#if (CD.x=0)
#local ShearX=0;
#else
#local ShearX=(CD.y/CD.x)*pow(CosThetaX, 2);
#end
#if (CD.z=0)
#local ShearZ=0;
#else
#local ShearZ=(CD.y/CD.z)*pow(CosThetaZ, 2);
#end
#declare NoFall=transform {
matrix <1, 0, 0, ShearX, 1, ShearZ, 0, 0, 1, 0, 0, 0>
}
#end
#declare CamPos=; //Just replace with location vector
#declare CamLook=; // -"- -"- with look_at vector
camera {
FieldCam (CamPos, CamLook)
perspective
location CamPos
transform { NoFall }
angle whatever //Don't forget to specify the angle :-)
look_at CamLook
}