Internet Ray Tracing Competition Entries

Nov-Dec 2000 - Contrast

London Gallery


The image

A view in a London gallery, showing a contrast between a painting of St Paul's Cathedral, and the real thing seen out the window.

How this image was created

No, that's not an image-map...

I tried to get several different contrasts into this image. The basic split is between an interior and an exterior view. The subject of each half of the image is the same, but one is a painting, the other reality. The painting shows a view of history, in wartime, with a dominating red, smoky colour scheme. The window shows the present day, in peace, with a bright blue sky. Another contrast, between the 334 year old cathedral and the modern NatWest Bank skyscraper and other buildings, is seen out the window. Finally, but probably most importantly to me, this image shows two contrasting ray-tracing styles that I use: realistic and impressionistic.

The painting is all CSG and procedural texturing. The lines are cylinders. I sketched a drawing of the cathedral on graph paper, and entered all the coordinates for the lines in by hand. The colouring is done with a group of squashed spheres, scaled and rotated variously and filled with coloured emission media. The painting is based on a famous World War II photograph taken of St Paul's Cathedral during the London Blitz. The objects are there in the final render. I could have rendered it separately and made it an image map, but doing it this way seems somehow more pure to me.

The picture frame is a set of prisms. I sketched the cross-section of the frames on my wedding photos and coded in the coordinates for a cubic spline prism. The plaque is fairly simple CSG with text objects cut out to form the words.

The buildings are all CSG, based on photographs from my research. There's not really much to say about them, except I used triply nested pigment maps to produce the cathedral dome texture, which was a first for me. There's a lot of layered textures there too.

Development History

I have an idea early on this time. This is the basic overall structural composition - though it may be tweaked a bit still. The wall could use a nicer texture, and the window frame could use some more modelling detail. The important parts will be:
  1. What is on the wall.
  2. What you can see out the window.
Actually, this image all by itself already shows one form of contrast: Indoors-Outdoors.

Here's something which will be seen out the window. It's not finished yet - there's more to go on the top, and a lot more to go underneath this bit. This is probably enough for this object to be recognisable though...

Okay, the second image shows this a bit more advanced. This is probably as much of this building as I need for the scene. Hopefully it should be clearly recognisable by now.

One of the books I am using as a reference actually describes this building as "a contrast" in architectural styles to the sort of building above. Independent confirmation that there will be contrast in the final scene!

So what's going to be on the wall next to that window? A picture frame! This frame is based on the frame shape of my wedding photos. I couldn't remember what the cross-sectional shape of a picture frame looked like in detail, so I sketched the cross section of one I had handy on some graph paper, and coded it in as a prism, with a cubic_spline.

And what goes in the picture frame? A picture of course!

Hmmm.... this looks familiar, and yet somehow a contrast.

This is not an image_map by the way. It's a collection of CSG objects.

All pictures need a label telling you what they are...


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