Some show off gems. Not that many really, as I usually produce images to show off functionality.
It doesn’t look much to the world, but it is the "hello world" of path tracing.
Just look at 'em bleed’n walls!
Image size: 800x400 Amount samples/pixel: 65536 Max recursion depth: 8 Amount facets: 18 Amount spheres: 2 Render date: 2023-03-14 Frame render time: 22h59m
The programming calendar "Advent of Code" 2022 gave a problem where you had to find the shortest path from one point to another given a height map and a couple of movement constraints from one coordinate in the map to another.
The shortest path was found using an A* search algorithm where each coordinate was a node and with, up to, 4 edges to adjacent coordinates (depending on the movement constraints).
The lava is just a texture added to the "a" height level for visual effect and not really part of the assignment. Looks cool though.
I could not help myself from trying to render an animation of the resulting path over the height map.
The animation can be viewed at Vimeo.
Amount frames: 1580 Image size: 250x250 Amount samples/pixel: 200 Max recursion depth: 4 Amount facets: 42624 Render date: 2023-02-19 Animation render time: aproximately (drum roll...) 72 hours
I will describe my thoughts on this simple scene. I might sound as I have put a lot of thought into this scene, but I really have not. I just have a vision of what I want to accomplish and try to realise as well as I can (without too much effort).
Well, the die is 3 cm in width, so it is a pretty large die…
But I wanted it to stand out in the image.
I am pretty pleased with the colors of both the cloth and the balls themselves.
The ball textures are drawn in inkscape. The font used is "Sofia Pro Soft". I found it after quite some research and evaluation as I wanted a quite professional billiard ball look and yet friendly appearance. The billiard balls were first placed in perfect positions with perfect distance from each other and facing strict towards the camera. But it was too perfect, so I added some random offset to the positions and random rotation as well to make them more dynamic.
The table cloth is an actually mobile photo taken by myself as I visited a billiard hall. The table cloth photo was made seamless using the make seamless online tool.
The lighting was set to warm color to mimic the warm lighting of dimmed low watt tungsten light bulbs. The warm light is 5000 Kelvin, whereas 6000 Kelvin is the white point reference (unfortunately not the standard D65).
I was thinking of implementing white color temperature myself solely using algorithm for CIE standard observer 2° and the properties of sRGB space, but I have too much other functionality abd things to do…
The dice textures was made using inkscape. The dice itself was made in Blender and exported as a Wavefront obj-file to be used in my own renderer. (Yeah, I know, not quite using the full potential of Blender…)
The billiard balls actually have a cylindrical projection on them. The number circle is too small at the center to have any noticeable distortion.
I will get back to this scene. It is still too clean. The balls should have som scratches and blue chalk dirt on them. The cloth should have imperfections as well. I guess I could fake it by adding random dirt to the textures but that would be rather dull.
It is much more fun to implement texture layers and normal mapping.
Image size: 1200x900 Amount samples/pixel: 16384 Max recursion depth: 4 Amount facets: 24 Amount spheres: 17 Render date: 2023-03-15 Frame render time: 12h44m
Really produced to show off the "free aperture shape" functionality.
Render date: 2023-02-25
Really produced to show off the cylindrical projection functionality.
Image size: 1024x576 Amount samples/pixel: 24576 Max recursion depth: 4 Amount facets: 208780 Amount spheres: 2 Render date 2023-03-19 Frame render time: 10h20m
This is a tribute to the blockbuster Cocktail (1988). Some 80’s nostalgia… (movie trailer)
Really produced to show off the transparency in texture with alpha channel.
Do pay attention to the neon sign. It is located 7 cm off the brick wall and leave a nice soft colored illumination to the wall. The light from the neon tubes is a little dim or weak to the ambient lighting as I could not help myself to add more lights like the morning sun through window blinds and soft (warm) spotlights along the top of the wall. Remember they did not have led strips that gave a continuous light along the wall in those days but had to use a trail of low voltage tungsten light bulbs.
The neon sign is actually three layers of transparent images stacked closely together (inter distance 3mm, thus "neon tube" is 6 mm thick). The middle layer is the light "halo" and layers in front and back of the halo are "core" light textures. They all emit light but the core is somewhat brighter than the halo. (See image at transparency in texture with alpha channel)
The huge amount of samples per pixels is really needed to avoid light noise as the "sun" shining through the window blinds is a very small but bright light source at the end of a pretty long light shaping box.
The "blinds" are actually like a "cut-out" shape from a cardboard at the front of a light shaping box. Well, of course it is not cardboard but a texture image at the front of the light shaping box. It can be any desired shape or form defined by a png-image with alpha channel transparency. Nifty and simple way of faking a window with blinds in wall with morning sunlight outside. (See image at transparency in texture with alpha channel)
Image size: 800x600 Amount samples/pixel: 24576 Max recursion depth: 10 Amount facets: 30 Amount spheres: 1 Render date: 2023-05-25 Render duration: 16h41m
The Cocktail logo is manually retraced in Inkscape from an original (?) found on the world spanning interconnected computer network for data exchange and communication.
It took me a weekend to tweak the lighting, but it was soo worth it.
I used two equirectangular "sky domes". One for the morning sky exterior and one for the cottage room interior. You can see the interior giving the room ambient light and reflecting in the porcelain tea pot, roughly in the kerosene lamp base and in the window glass. It is a quite important detail at a unconscious level that probably is missed at first glance, but it gives the scene a whole new level realism.
The soot smudge on the kerosene lamp glass is on a separate facet structure just inside the lamp glass to make sure the glass can still reflect the ambient room.
The tea pot is of course The Utah Tea Pot, but not the original set of facets but a high resolution and "water tight" version. Along with the matching tea cup and spoon. The tea cup object is altered to have bottom facets and separate structures for the saucer and the cup.
The wall paper and the table cloth are actual wall paper test images from a wall paper manufacturer.
There is no "tea" in the cup nor in the tea pot. Camera angle is chosen with care to avoid a peek inside…
Render algorithm: Pathtracing Image size: 1200x900 Amount samples/pixel: 43008 Max recursion depth: 10 Amount facets: 510546 Amount spheres: 1 Render date: 2023-06-01 Render duration: 61h43m
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Note
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The Utah teapot (as well as tea cup and spoon) is originally from a bezier patch data set created by Martin Edward Newell in 1975 and rendered images of the tea set can be found in the journal article "The utilization of procedure models in digital image synthesis" (1976). A facet based data set is more often used than the original bezier data. The real tea pot is still in production by the Friesland Porzellan companey, once part of the German Melitta group. The reason rendered versions of the teapot is 3/4 the height of the real teapot is that it was considered more pleasing to look at as Jim Blinn (yes, creator of Blinn-Phong) rescaled it as a demonstration that the computer model could be manipulated. |
This image is a spin-off from the "Early morning tea at the cottage" when I fiddled with parameters to get the materials right for the kerosene lamp.
Render algorithm: Pathtracing Image size: 600x800 Amount samples/pixel: 24576 Max recursion depth: 10 Amount facets: 7250 Amount spheres: 1 Render date: 2023-05-31 Render duration: 7h56m