"Worldbowl"

The Idea

The topic was given by the IRTC's round of Jan-Feb 2002, "World within Worlds". This was I went for straight ahead, a world contained in a glassbowl, envisioned much like a lavalamp...

The Worldbowl-Scenery

1. Step - The landscape

I needed a landscape which would be cut off by the glassbowl, as well as extremely small and detailed. Since image-maps are rather hard to get more detailed, I went for the pigment-functions of the new POV Betas and designed a pigment. This would supply the base for the heightfield. Then, using clipped_by and CSG, three objects compromise the landscape:

A clipped heightfield-object, a disc to make sure there are no gaps between heightfield and bowl, and a heightfield-clipped sphere.

Using the new slope-maps, the heightfield was textured according to height and slope. Since the mountainscape seen in the bowl is meant to be extremely small-scale, no objects were placed. I considered placing trees and some huts, but decided that it could ruin the scale and quality.

2. Step - The ocean

For the water to look enclosed, there is something very important to know: you may only apply bumpmapping onto the surface that does not touch any glass. To do that, I used a box-intersected sphere (matching a declared waterheight) with a non-normal texture. On top of that, a disc, matching the interior size of the glassbowl, was placed, using the same texture, but with a normal applied.

3. Step - The clouds

First idea many people'd have would be to go for scattering media or isosurfaces. I went for the "stacked planes" technique. I placed several discs with a slightly transparent pigment on top of each other. The pigment was changed inside the loop, in order to adjust the bozo pattern's colormap. Add some thought, trial and error, and voila! There you have pretty realistic, volumetric, though tracing-intensive clouds.

4. Step - The lamp's lightsources

I've used a new approach: lightsources with rgb-values as high as 10, but with a quick fade using fade_power and fade_distance parameters. With a lot of tweaking and the use of artistic freedom, there are two spotlights. One is pointing at the clouds and the bowl itself, casting the main light. The second spotlight is positioned and sized to fill the lampshade with extreme lighting. This way, when viewed directly, you'll see a white area inside the shade, but in the window's reflection, you'll actually see the lightbulb.

Another fading, but also shadowless lightsource was positioned to lighten the entire scene up a bit, simulating radiosity.

5. Step - The Glassbowl itself

The bowl itself is simple CSG, as well as the wooden-like base. The lamp and the cable were done using a bezier-macro I wrote and placing several hundreds of spheres and cylinders along a spline.

The Realworld-Scenery

1. Step - Main background (Sky)

I've used the same approach as in the glassbowl itself. 30 planes, stacked with the same pattern. The colors were adjusted to fit to the night scenery. The ocean is a single plane, with a heavily turbulenced normal pattern. No specular or phong highlighting was used, but only exponential reflection. The Moon is an actual sphere placed according to a lightsource, which doesn't have much impact on the foreground scenery, but on the lighting of the clouds. The sphere was wrapped with the original image-map of the real moon, in the ZIP you'll find a smaller PNG Version. I altered the greyscale color of the moon to something more purplish, artistic freedom, thanks! The moon's glow was achieved combining faked flares (a transparent disc slightly in front of camera) with a sky_sphere pattern. Gives an atmospheric touch to the sky, as well as slight blinding sensation to the image.

2. Step - The room

The room was constructed using simple CSG and carving a rudimentary space out of a box. Nothing really special. The table consists of several instances of a mesh, which basically provides one tile: some tiles placed in a loop. Only one simple cylinder-leg was placed, the others wouldn't be visible and were thus not placed. The window was made using CSG, and the strange effect you may see in the frame is actually pretty realistic: the edges of windows (at least in my windows) do reflect near-mirror like. So there's not an artifact appearance, but close-detail.

3. Step - The "various" items

The flowers were created with a loop. After I've modelled a single leaf by clipping a sphere with a cubic-spline-prism, it was placed, rotated and scaled in order to get the basic, stylistic flower. The stems are made of spheres and cylinders, using my bezier-macro, much like the lamp and the cable from the worldbowl. The vase is a simple cubic-spline-lathe.

The notebook is made of several parts. The first is a box, image-mapped with the writing (PNG found in ZIP). The second is a spline-based mesh, which creates the "flapped" page. The curl on the writing was done using a loop to calculate the positions for some dozens of triangles.

The pencil is made of two parts: a hexagon-shaped prism intersected with a cone for the tip, and the hexagon-shaped prism for the remaining section.

The picture on the wall is one of my older images, of which you'll also find a smaller PNG version in the ZIP.

Scene Settings

I tweaked the default ambient-light to .01 to give a very dark appearance. In the beginning, this resulted in too dark images, but using the shadowless lightsource solved that problem. The "stacked planes technique" required a way higher max_trace_level that I was normally used to, and thus reflections took longer than before. But patience is something every pure POVer should have... At first, I did want to use arealights, but tracing times rocketed into the sky, and thus left that be. Focal-blur was also considered in the initial phases, but considering that some 40 lines took about a day on my fairly fast computer, I dropped that. I just didn't have the time to wait some weeks...

The Lighting

There is one point-lightsource used for the moon's lighting, positioned just in front of it, but behind the stacked clouds.

Another spotlight points away from the obvious lamp on the desk, whereas another spotlight points towards the head of the lamp. This achieves an interesting effect: in reflections (like in the window), you can actually see the lightbulb, whereas viewed directly, its just overlit. Looks pretty real to me.

Personal Note

I'm really proud of this one, since it has got many little details and some very realistic clouds, in my oppinion at least. In 2003 I improved extensively on this image, but lost the data after my harddrives fried themselves. Too bad. :-(