Raspberry Pi 3d demo.

This uses the peterderivaz's bindings to the EGL and OpenGLES libraries to draw 3d graphics from inside Python with hardware acceleration (via ctypes and ctypes.CDLL)

Running

The scripts should Just Work (tested on the latest debian image). If you are on Arch, you may have to add the "/opt/vc/lib" directory to your ld.conf so that ldd can find them.

Demo Scripts

I wrote the 'Hello_*' scripts as a learning tool for myself and they are quite rough around the edges. I would appreciate any feedback/patches to make them better!

01_Hello_Triangle.py

A large red triangle.

This script shows the minimum setup required to use OpenGL ES 2.0, from getting a display, loading shaders, linking and creating a (small) Vertex Buffer Object (VBO) for the triangle.

02_Hello_Rotating_Triangle.py

A large triangle, but this time, you can rotate it using the m and n keys. The rotation of the triangle is done within the shader.

03_Hello_Moving_Triangle.py

Extension of 02, showing how to translate a set of vertices.

04_Hello_Aspect_Ratio.py

How to scale and correct the aspect ratio of the rendering to match that of the display.

GLSL 'sandbox'

"glsl_sandbox.sh" is an attempt to provide some support to running the shader examples from @mrdoob's GLSL sandbox: http://glsl.heroku.com/ and uses 'nano' (and pyinotify) to allow for live updates.

Prerequisites: sudo apt-get install python-pyinotify

Usage:

Run a shader stored in a file: bash glsl_sandbox.sh leds.glsl

Interactive: python -i env_glsl.py

>>> frag = """
uniform float time;
uniform vec2 mouse;
uniform vec2 resolution;

void main()
{

	vec2 position = -1.0 + 2.0 * (gl_FragCoord.xy / resolution.xy);
	position.x *= resolution.x / resolution.y;
	
	position += vec2(cos(time * 0.25), sin(time * 0.5)) * 0.8;

	vec3 colour = vec3(0.0);
	
	float u = sqrt(dot(position, position));
	float v = atan(position.y, position.x);
	
	float t = time + 1.0 / u;
	
	float val = smoothstep(0.0, 1.0, sin(5.0 * (time + sin(1.0*u * 3.7)) + 10.0 * v) + cos(t * 10.0));
	
	colour = vec3(val / 0.1, val, 0.0) + (0.9 - val) * vec3(0.05, 0.05, 0.05);
	colour *= clamp(u / 1.0, 0.0, 1.0);
	
	gl_FragColor = vec4(colour, 1.0);

}
"""
>>> run_shader(f)
Compiled GL_VERTEX_SHADER shader
Compiled GL_FRAGMENT_SHADER shader

[NB Press Ctrl-C to quit the render and get back to the commandline]

Forked from @peterderivaz's pyopengles bindings, which have been made into a loadable module in pyopengles.

dreamlayers / pyopengles