From e95c6d5d1c6253a2b05176a205ad1448c2930aac Mon Sep 17 00:00:00 2001 From: Adrian Kummerlaender Date: Sat, 21 Sep 2019 18:20:29 +0200 Subject: Play around with volumetric rendering using ray marching --- channel_3d_volumetric_rendering_gl_interop.py | 302 ++++++++++++++++++++++++++ 1 file changed, 302 insertions(+) create mode 100644 channel_3d_volumetric_rendering_gl_interop.py diff --git a/channel_3d_volumetric_rendering_gl_interop.py b/channel_3d_volumetric_rendering_gl_interop.py new file mode 100644 index 0000000..b3be853 --- /dev/null +++ b/channel_3d_volumetric_rendering_gl_interop.py @@ -0,0 +1,302 @@ +import numpy +from string import Template + +from simulation import Lattice, Geometry +from utility.particles import Particles +from symbolic.generator import LBM + +import symbolic.D3Q27 as D3Q27 + +from OpenGL.GL import * +from OpenGL.GLUT import * + +from OpenGL.GL import shaders + +from pyrr import matrix44, quaternion + +from geometry.sphere import Sphere +from geometry.box import Box +from geometry.cylinder import Cylinder + +from utility.opengl import MomentsTexture + +lattice_x = 256 +lattice_y = 64 +lattice_z = 64 + +updates_per_frame = 10 + +lid_speed = 0.05 +relaxation_time = 0.51 + +def get_cavity_material_map(g): + return [ + (lambda x, y, z: x > 0 and x < g.size_x-1 and + y > 0 and y < g.size_y-1 and + z > 0 and z < g.size_z-1, 1), # bulk fluid + (lambda x, y, z: x == 1 or x == g.size_x-2 or + y == 1 or y == g.size_y-2 or + z == 1 or z == g.size_z-2, 2), # walls + (lambda x, y, z: x == 1, 3), # inflow + (lambda x, y, z: x == g.size_x-2, 4), # outflow + + (Sphere(3*g.size_x//20, g.size_y//2, g.size_z//2, 28), 5), + (Sphere(1*g.size_x//20, g.size_y//2, g.size_z//2, 12), 1), + (Sphere(3*g.size_x//20, g.size_y//2, g.size_z//2, 16), 1), + (Sphere(5*g.size_x//20, g.size_y//2, g.size_z//2, 16), 1), + + (lambda x, y, z: x == 0 or x == g.size_x-1 or + y == 0 or y == g.size_y-1 or + z == 0 or z == g.size_z-1, 0) # ghost cells + ] + +boundary = Template(""" + if ( m == 2 || m == 5 ) { + u_0 = 0.0; + u_1 = 0.0; + u_2 = 0.0; + } + if ( m == 3 ) { + u_0 = min(time/5000.0 * $inflow, $inflow); + u_1 = 0.0; + u_2 = 0.0; + } + if ( m == 4 ) { + rho = 1.0; + } +""").substitute({ + "inflow": lid_speed +}) + +def get_projection(width, height): + world_width = lattice_x + world_height = world_width / width * height + + projection = matrix44.create_perspective_projection(20.0, width/height, 0.1, 1000.0) + look = matrix44.create_look_at( + eye = [0, -2*lattice_x, 0], + target = [0, 0, 0], + up = [0, 0, -1]) + + point_size = 1 + + return numpy.matmul(look, projection), point_size + +class Rotation: + def __init__(self, shift, x = numpy.pi, z = numpy.pi): + self.shift = shift + self.rotation_x = x + self.rotation_z = z + + def update(self, x, z): + self.rotation_x += x + self.rotation_z += z + + def get(self): + qx = quaternion.Quaternion(quaternion.create_from_eulers([self.rotation_x,0,0])) + qz = quaternion.Quaternion(quaternion.create_from_eulers([0,0,self.rotation_z])) + rotation = qz.cross(qx) + return numpy.matmul( + matrix44.create_from_translation(self.shift), + matrix44.create_from_quaternion(rotation) + ) + +def glut_window(fullscreen = False): + glutInit(sys.argv) + glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH) + + if fullscreen: + window = glutEnterGameMode() + else: + glutInitWindowSize(800, 500) + glutInitWindowPosition(0, 0) + window = glutCreateWindow("LBM") + + return window + +lbm = LBM(D3Q27) + +window = glut_window(fullscreen = False) + +vertex_shader = shaders.compileShader(Template(""" +#version 430 + +layout (location=0) in vec4 vertex; + out vec3 color; + +uniform mat4 projection; +uniform mat4 rotation; + +void main() { + gl_Position = projection * rotation * vertex; + color = vec3(1.0,1.0,1.0); +}""").substitute({}), GL_VERTEX_SHADER) + +fragment_shader = shaders.compileShader(""" +#version 430 + +in vec3 color; + +void main(){ + gl_FragColor = vec4(color.xyz, 0.0); +}""", GL_FRAGMENT_SHADER) + +lighting_vertex_shader = shaders.compileShader(""" +#version 430 + +layout (location=0) in vec4 vertex; + out vec3 frag_pos; + +uniform mat4 projection; +uniform mat4 rotation; + +void main() { + gl_Position = projection * rotation * vertex; + frag_pos = vertex.xyz; +}""", GL_VERTEX_SHADER) + +lighting_fragment_shader = shaders.compileShader(Template(""" +#version 430 + +in vec3 frag_pos; + +uniform mat4 rotation; + +uniform sampler3D moments; + +out vec4 result; + +vec3 unit(vec3 v) { + return vec3(v[0] / $size_x, v[1] / $size_y, v[2] / $size_z); +} + +float norm(vec3 v) { + return v[0]*v[0] + v[1]*v[1] + v[2]*v[2]; +} + +vec3 blueRedPalette(float x) { + return mix( + vec3(0.0, 0.0, 1.0), + vec3(1.0, 0.0, 0.0), + x + ); +} + +void main(){ + const vec4 light_pos = rotation * vec4(0,-2*$size_x,0,1); + + const vec3 ray = normalize(frag_pos - light_pos.xyz); + + vec4 color = vec4(0.0,0.0,0.0,1.0); + const float ray_length = 128.0; + + for (float t = 1.0; t < ray_length; t += ray_length/80.0) { + const vec3 sample_pos = unit(frag_pos + t*ray); + if (norm(sample_pos) < 3.05) { + const vec4 data = texture(moments, sample_pos); + if (data[3] != 1.0) { + const float norm = sqrt(data[1]*data[1]+data[2]*data[2]+data[3]*data[3]) / ($lid_speed); + color.rgb += 0.05 * (1.0 - t/ray_length) * blueRedPalette(0.5*norm); + } else { + color.rgb += 0.03; + } + } else { + break; + } + } + + result = color; +} +""").substitute({ + "size_x": lattice_x, + "size_y": lattice_y, + "size_z": lattice_z, + "lid_speed": lid_speed +}), GL_FRAGMENT_SHADER) + +domain_program = shaders.compileProgram(vertex_shader, fragment_shader) +projection_id = shaders.glGetUniformLocation(domain_program, 'projection') +rotation_id = shaders.glGetUniformLocation(domain_program, 'rotation') + +obstacle_program = shaders.compileProgram(lighting_vertex_shader, lighting_fragment_shader) +projection_id2 = shaders.glGetUniformLocation(obstacle_program, 'projection') +rotation_id2 = shaders.glGetUniformLocation(obstacle_program, 'rotation') + +lattice = Lattice( + descriptor = D3Q27, + geometry = Geometry(lattice_x, lattice_y, lattice_z), + moments = lbm.moments(optimize = True), + collide = lbm.bgk(f_eq = lbm.equilibrium(), tau = relaxation_time), + boundary_src = boundary, + opengl = True +) + +moments_texture = MomentsTexture(lattice) + +material_map = get_cavity_material_map(lattice.geometry) +primitives = list(map(lambda material: material[0], filter(lambda material: not callable(material[0]), material_map))) +lattice.apply_material_map(material_map) +lattice.sync_material() + +rotation = Rotation([-lattice_x//2, -lattice_y//2, -lattice_z//2]) + +cube_vertices, cube_edges = lattice.geometry.wireframe() + +def on_display(): + for i in range(0,updates_per_frame): + lattice.evolve() + + moments_texture.collect() + + glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT) + + glEnable(GL_DEPTH_TEST) + glDepthFunc(GL_LESS) + + shaders.glUseProgram(obstacle_program) + glUniformMatrix4fv(projection_id2, 1, False, numpy.ascontiguousarray(projection)) + glUniformMatrix4fv(rotation_id2, 1, False, numpy.ascontiguousarray(rotation.get())) + moments_texture.bind() + Box(0,lattice.geometry.size_x,0,lattice.geometry.size_y,0,lattice.geometry.size_z).draw() + + shaders.glUseProgram(domain_program) + glUniformMatrix4fv(projection_id, 1, False, numpy.ascontiguousarray(projection)) + glUniformMatrix4fv(rotation_id, 1, False, numpy.ascontiguousarray(rotation.get())) + glLineWidth(4) + glBegin(GL_LINES) + for i, j in cube_edges: + glVertex(cube_vertices[i]) + glVertex(cube_vertices[j]) + glEnd() + + glutSwapBuffers() + +def on_reshape(width, height): + global projection, point_size + glViewport(0,0,width,height) + projection, point_size = get_projection(width, height) + +def on_keyboard(key, x, y): + global rotation + + x = { + b'w': -numpy.pi/20, + b's': numpy.pi/20 + }.get(key, 0.0) + z = { + b'a': numpy.pi/20, + b'd': -numpy.pi/20 + }.get(key, 0.0) + + rotation.update(x,z) + +def on_timer(t): + glutTimerFunc(t, on_timer, t) + glutPostRedisplay() + +glutDisplayFunc(on_display) +glutReshapeFunc(on_reshape) +glutKeyboardFunc(on_keyboard) +glutTimerFunc(10, on_timer, 10) + +glutMainLoop() -- cgit v1.2.3