EMAIL: gary@mackinnon.com
NAME: Gary MacKinnon
TOPIC: Winter
COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT.
TITLE: Almost Home
COUNTRY: USA
WEBPAGE: 
RENDERER USED: Pov-ray 3.5 beta 15
TOOLS USED: Paint Shop Pro to convert to jpg.
RENDER TIME: About a week.
HARDWARE USED: Athlon 1700 with 1GByte Ram 
IMAGE DESCRIPTION:

This scene contrasts the cold, snowy and dreary outdoor environment with the warm and inviting indoors.  The outside is characterized by cold blueish pigments, pealing paint and stains on a poorly maintained window.  Inside pigments are warm and yellow.  There is a roaring fire, carpet and the symbol of a warm family, a Christmas tree. 

DESCRIPTION OF HOW THIS IMAGE WAS CREATED:

Well there is a lot here but I will try to be brief.  This is my second IRTC entry.  This was all done in Pov-ray script.  No modeller was used.  

Outside lighting comes from an area light to soften the shadows.

The falling snow is random prisms with a bozo pigment map of White and transparent colors. 

The snow on the window sill is an isosurface with noise and trimmed by planes.  

The pealing paint came from a technique that Christophe Bouffartigue used in an IRTC entry called CBWOR. Unfortumately the dull lighting and the snow diminishes the visibility of the effect here. 

The frost on the glass is two intersecting isosurfaces with noise functions.  One surface is a circle modified with low frequeny noise and forms the top random edge.  The facing surface is a higher frequency noise.  The frost is semi-transparent. Each panel is different.

The Christmas tree was a challenge. I first thought of modeling every needle but the tree would require millions.  Instead a segment of a branch was modeled as a cylinder with a bozo pigment map surface of green and transparent colors.  A wood colored thin cylinder ran down the the center of the branch segment.  The branch segments were assembled into branches with some randomness in the placements and the branches were assembled into the tree again with randomness.  The effect from a distance was not bad. Something similar was done for the wreath. 

The lights of the tree were placed somewhat randomly but toward the outer edge of the tree.  The placement macro also prevented lights from being placed too close to each other.  Unless you add this check you get unrealistic clusters of the lights.  The lights had a fade distance of about three inches.  The lights slow down the rendering tremendously and to keep it from getting completely out of hand the lights are only placed on the roughly 30% of the tree that is visible. I tried using the light_group construct to speed up rendering but it seems to have limited applicability.  It could not see the light bulbs that were placed using a macro even though the macro was inside the light_group construct.  Anyway the rendering takes many days on a fairly fast machine and 1 Gb RAM is needed.

The fire is an emitting media.  The density was formed using a function in x,y,z which created a conic shape which was then warped to create the random flames.  The density was then painted with a color map ranging basically from black to red to yellow. 

The sconces were hard to get the effect I wanted. I was hoping to model the light and material properties accurately and Pov-ray would do the rest but I ended up having to use some extra lights.  An image map was used for the mica surface. This was made semi-transparent and at a high ambience. A bright light bulb was placed inside the sconce to create the bright area that you see on the mica. However this created unrealistic lighting outside the sconce so the fade distance was shortened to a few inches and a second light was placed inside the sconce.  Finally, a third light was placed outside the sconce to effectively light the surrounding area. 

The light falling on the window and sill comes from another interior light off to the right.

Appologies for not including the source files but my Pov-ray environment is now a collection of intertwined include files from which the applicable code for a single image is not easily extracted. I will be happy to send code fragments to anyone who inquires about any of the components.