3D Texture using GLScene.
Evaluate to 3D Texture is a program that lets you specify a formula, that determines the properties of a 3D texture.
The textures become fairly large, even though I only use a resolution of 64x64x64 pixels, with 4 bytes of color data per pixel (Red, Green, Blue and Aplha channel). That comes out to 1024 kb. The system could easily handle 128x128x128 pictures, but generating them becomes prohibitive. Rendering at 64^3 takes 5 seconds on my computer. Rendering at 128^3 should take about 40 seconds.
The original code was created by Jens Krüger, and can be found here. Eric Grange ported the demo to GLScene, and Jürgen Abel and Ivan Lee Herring made changes to the code. Jurgen Abel made the x/y/z cutting plane.
The Evaluate code was created by mattias fagerlund, I am also maintained this page.
Showing still 2D versions of the images don't do them justice - each of these textures can be rotated in real time on a fast computer, showing them from any angle with transparancy and all. But all the same, here are a couple of 2D renderings for you to look at. Below each image you can see the formula used to generate the image.
SetPixelRGBA(x, (x+y)/2, z, Max(x/6, IfThen(r-0.5,0,1)))
SetPixelRGBA(x, (x+y)/2, z, IfThen(r-0.7,1,0))
IfThen(r-0.7, SetPixelRGBA(x, (x+y)/2, z, 1), SetPixelBWA(1, r/8))
Same as above, but using a much lower resolution
(Function is fairly complex, download demo)
(Another complex function)
Noise example
Noise example
Noise example
If you create any interesting images, please send the code to me, and I'll include it in the latest distro.
Note that the first time you run the demo, you will be required to generate a 3D Texture, because none are included in the download. The code requires a late model gfx card to function properly.
Click here to download the 3DTexture demo.
Size=352,06 kb, created 2005-10-04 07:04:08.
Click here to download the full source - requires late version (CVS) of GLScene.
Size=933,47 kb, created 2005-10-04 07:04:03.
Click here to download the source only (no bin) - requires late version (CVS) of GLScene.
Size=23,73 kb, created 2005-02-28 19:39:36.
The language that describes the formulas is actually quite simple, try to follow the examples and you should be allright. If you find a formula that's valid and won't compile, please send it to me. If you find a formula that's invalid, and makes the program crash, please send it to me.
|
Operator / Operand name |
Description | |
| x / y / z | Returns x,y and z value of the pixel being painted, in the range 0 to 1 | |
| ox / oy / oz | Returns x,y and z value of the pixel being painted, but in the range -1 to 1. | |
| r | The distance from the center of the cube, in the range 0 to 1 | |
| Constants | Use '.' for decimals, as in
0.75 or 23.23. Of course, values without decimals are also valid. |
|
| Parenthesis | Parenthesis work as you'd expect, go ahead and use them! | |
| SetPixelRGBA | Will set the color and alpha of the pixel to four distinct
values. It takes three arguments, corresponding to Red, Green, Blue and
Alpha values. Values are capped to [0..1] SetPixelRGBA(Red, Green, Blue, Alpha) |
|
|
SetPixelBWA |
Will set the color
of the pixel and the alpha of the pixel to two distinct values.
All pixels outputted using this method will be grey, because R=G=B. See
SetPixelRGBA for more information. SetPixelBW(RGB, Alpha) |
|
| SetPixelBW | Will set the color and alpha of the pixel to a single value.
All pixels outputted using this method will be grey, because R=G=B. See
SetPixelRGBA for more information. SetPixelBW(RGBAndAlpha) |
|
| +, *, /, - | Function as you would expect. SetPixelBWA(x*(z-0.5)+y*2-3, 0.3) |
|
| > | Returns true (1) if first
argument is larger than second argument. Otherwise it returns false (-1) x>y |
|
| < | see > | |
| Max | Requires two arguments, returns the bigger of the two | |
| Min | Requires two arguments, returns the smaller of the two | |
| Sin | Requires one argument, returns the sine | |
| OSin | A modified version of sin, that
works in the range of 0 to 1 and returns values in the range 0 to 1 OSin(x)=(Sin(x*2*pi+1)/2 |
|
| Abs | Requires one argument, returns the absolute value (always positive) | |
| SQR | Requires one argument, returnes the square of the argument | |
| SQRT | Requires one argument, returnes the square root of the argument | |
| IfThen | Requres three arguments. If the first argument is above
zero, the second argument is executed. If the first argument is below or
equal to zero, the thirg argument is executed. IfThen(Test, IfTrue, IfFalse) |
|
| And | Requires two arguments, returns
true (1) if both are true (>0), otherwise it returns false (-1).
IfThen(and(x>0.2,y>0.2), 1, 0) |
|
| Or | Works like and, but instead of and it ors. Or? | |
| Xor | Works like or, but only if one of them. Xor? | |
| NoiseXYZ | Basic perlin noise function.
Requires three arguments that determin the noise behavoiur. Typically, you
would input x,y,z - but you can imput anything you want. |
|
| NoiseFull | Similar to basic noise function
but also implements amplitude and octave. It requires 5 arguments
(x,y,z,octave and amplitude). NoiseFull(ax, ay, az, oct, amp)=NoiseXYZ(ax*Oct, ay*Oct, az*Oct)*Amp |
|
| NoiseOctAmp | Another noise function that uses
the image x,y,z - you don't need to input them. NoiseOctAmp(Oct, Amp) = NoiseXYZ(x*Oct, y*Oct, z*Oct)*Amp Typically, you will want to add several octaves with different amplitudes for a nice noise pattern; SetPixelBWA(1, |
|
| ? | Feel free to suggest further functions |
If you have any questions, suggestions or comments, don't hesitate to email the to me at mattias@hypeskeptic.com.
