我想在webgl2中制作一个带有三角形网格的raytracer。我问了另一个问题，我得到了一些示例代码来做到这一点。
为了在着色器中访问所有三角形并与三角形执行射线相交，网格数据需要存储在纹理中。这是我稍加修改的代码：
(() => {
'use strict';
// vertex
const vs = `#version 300 es\n
in vec2 p;
out vec2 vuv;
void main(){
gl_Position = vec4(vuv = p, 0, 2);
}`;
// fragment
const fs = `#version 300 es\n
precision highp float;
precision highp int;
precision highp sampler2D;
in vec2 vuv;
uniform float time;
uniform vec2 Res, mouse;
uniform sampler2D uMeshData;
uniform int vertsCount;
layout(location = 0) out lowp vec4 fragColor;
struct Ray {
vec3 orig, dir;
}R_;
mat4 rotate() {
float x = mouse.x, y=mouse.y+sin(time*2.),z=0.;
float a = sin(x), b = cos(x), c = sin(y), d = cos(y), e = sin(z), f = cos(z), ac = a * c, bc = b * c;
return mat4(d * f, d * e, -c, 0.0,
ac * f - b * e, ac * e + b * f, a * d, 0.0,
bc * f + a * e, bc * e - a * f, b * d, 0.0,
0.0, 0.0, 0.0, 1.0);
}
// https://github.com/Jojendersie/gpugi/blob/5d18526c864bbf09baca02bfab6bcec97b7e1210/gpugi/shader/intersectiontests.glsl#L63
bool isTriangle(Ray ray, in vec3 p0, in vec3 p1, in vec3 p2, out vec3 N) {
vec3 e0 = p1 - p0, e1 = p0 - p2;
N = cross(e1, e0);
vec3 e2 = (1.0 / dot(N, ray.dir)) * (p0 - ray.orig);
vec3 i = cross(ray.dir, e2);
vec3 b = vec3(0.0, dot(i, e1), dot(i, e0));
b.x = 1.0 - (b.z + b.y);
return (dot(N, e2) > 1e-8) && all(greaterThanEqual(b, vec3(0.0)));
}
void Camera(out Ray ray, vec3 lookAt, vec3 up, float angle, float aspect) {
vec3 g = normalize(lookAt - ray.orig);
vec3 u = normalize(cross(g, up));
vec3 v = normalize(cross(u, g));
u = u * tan(radians(angle * .5));
v = v * tan(radians(angle * .5)) / aspect;
ray.dir = normalize(g + ray.dir.x * u + ray.dir.y * v);
}
void main() {
vec3 SceneCol = vec3(0.5);
vec3 hit = vec3(0.);
vec4 a = vec4(0.0), b = vec4(0.0), c = vec4(0.0);
R_ = Ray(vec3(0.0, 0.0, 3.0), vec3(vuv, -1.));
Camera(R_, vec3(0., 0., 1.), vec3(0., 1., 0.), 90.0, (Res.x / Res.y));
float mindist = -1000.0;
// here comes this importend part unpack the texture
for (int i = 0; i < vertsCount; i += 3)
{
a = rotate() * texelFetch(uMeshData, ivec2(i, 0), 0);
b = rotate() * texelFetchOffset(uMeshData, ivec2(i, 0), 0, ivec2(1, 0));
c = rotate() * texelFetchOffset(uMeshData, ivec2(i, 0), 0, ivec2(2, 0));
if (isTriangle(R_, a.xyz, b.xyz, c.xyz, hit))
{
float z = hit.z;
if (z > mindist) {
mindist = z;
SceneCol.rgb = vec3(hit.x, hit.y, 1. - (hit.x - hit.y));
};
}
}
vec3 sky = vec3(0.5, 0.25, 0.1) * (-R_.dir.y - 0.1);
fragColor.rgb = SceneCol + sky;
fragColor.a = 1.0;
}`;
const canvas = document.getElementById('c');
const gl = canvas.getContext('webgl2', {
alpha: !1,
depth: !1,
stencil: !1,
antialias: !1,
premultipliedAlpha: !1,
presereDrawingBuffer: !1,
failIfMajorPerformanceCaveat: !1
});
const { width, height } = canvas.getBoundingClientRect();
console.log(width, height)
gl.canvas.width = width; //window.innerWidth;
gl.canvas.height = height; //window.innerHeight;
// init
const P = gl.createProgram();
const Fp = gl.createShader(gl.FRAGMENT_SHADER);
gl.shaderSource(Fp, fs);
gl.compileShader(Fp);
if (!gl.getShaderParameter(Fp, gl.COMPILE_STATUS)) throw '! F r a g: ' + gl.getShaderInfoLog(Fp);
gl.attachShader(P, Fp);
const Vp = gl.createShader(gl.VERTEX_SHADER);
gl.shaderSource(Vp, vs);
gl.compileShader(Vp);
if (!gl.getShaderParameter(Vp, gl.COMPILE_STATUS)) throw '! V e r t: ' + gl.getShaderInfoLog(Vp);
gl.attachShader(P, Vp);
// link use program
gl.linkProgram(P);
gl.useProgram(P);
// uniform location
const time_loc = gl.getUniformLocation(P, 'time');
const res_loc = gl.getUniformLocation(P, 'Res');
const uLvertices = gl.getUniformLocation(P, 'vertsCount');
const uLSr = gl.getUniformLocation(P, 'uMeshData');
const mouse_loc = gl.getUniformLocation(P, 'mouse');
// free resources
gl.detachShader(P, Fp);
gl.detachShader(P, Vp);
gl.deleteProgram(P);
// fullscreen quad
gl.bindBuffer(gl.ARRAY_BUFFER, gl.createBuffer());
gl.bufferData(gl.ARRAY_BUFFER, new Int8Array([-4, 2, 2, -4, 2, 2, -4, 2, -4, -4, 2, -4 ]), gl.STATIC_DRAW);
gl.enableVertexAttribArray(0);
gl.vertexAttribPointer(0, 2, gl.BYTE, !1, 0, 0);
gl.bindVertexArray(null);
// bind texture
const texture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, texture);
// blender 2.79 Icosphere
// export -> *.raw (needs to be enable first under settings)
const verts = [
0.000000, 0.000000, -1.000000, 0.425323, -0.309011, -0.850654, -0.162456, -0.499995, -0.850654,
0.723607, -0.525725, -0.447220, 0.425323, -0.309011, -0.850654, 0.850648, 0.000000, -0.525736,
0.000000, 0.000000, -1.000000, -0.162456, -0.499995, -0.850654, -0.525730, 0.000000, -0.850652,
0.000000, 0.000000, -1.000000, -0.525730, 0.000000, -0.850652, -0.162456, 0.499995, -0.850654,
0.000000, 0.000000, -1.000000, -0.162456, 0.499995, -0.850654, 0.425323, 0.309011, -0.850654,
0.723607, -0.525725, -0.447220, 0.850648, 0.000000, -0.525736, 0.951058, -0.309013, 0.000000,
-0.276388, -0.850649, -0.447220, 0.262869, -0.809012, -0.525738, 0.000000, -1.000000, 0.000000,
-0.894426, 0.000000, -0.447216, -0.688189, -0.499997, -0.525736, -0.951058, -0.309013, 0.000000,
-0.276388, 0.850649, -0.447220, -0.688189, 0.499997, -0.525736, -0.587786, 0.809017, 0.000000,
0.723607, 0.525725, -0.447220, 0.262869, 0.809012, -0.525738, 0.587786, 0.809017, 0.000000,
0.723607, -0.525725, -0.447220, 0.951058, -0.309013, 0.000000, 0.587786, -0.809017, 0.000000,
-0.276388, -0.850649, -0.447220, 0.000000, -1.000000, 0.000000, -0.587786, -0.809017, 0.000000,
-0.894426, 0.000000, -0.447216, -0.951058, -0.309013, 0.000000, -0.951058, 0.309013, 0.000000,
-0.276388, 0.850649, -0.447220, -0.587786, 0.809017, 0.000000, 0.000000, 1.000000, 0.000000,
0.723607, 0.525725, -0.447220, 0.587786, 0.809017, 0.000000, 0.951058, 0.309013, 0.000000,
0.276388, -0.850649, 0.447220, 0.688189, -0.499997, 0.525736, 0.162456, -0.499995, 0.850654,
-0.723607, -0.525725, 0.447220, -0.262869, -0.809012, 0.525738, -0.425323, -0.309011, 0.850654,
-0.723607, 0.525725, 0.447220, -0.850648, 0.000000, 0.525736, -0.425323, 0.309011, 0.850654,
0.276388, 0.850649, 0.447220, -0.262869, 0.809012, 0.525738, 0.162456, 0.499995, 0.850654,
0.894426, 0.000000, 0.447216, 0.688189, 0.499997, 0.525736, 0.525730, 0.000000, 0.850652,
0.525730, 0.000000, 0.850652, 0.162456, 0.499995, 0.850654, 0.000000, 0.000000, 1.000000,
0.525730, 0.000000, 0.850652, 0.688189, 0.499997, 0.525736, 0.162456, 0.499995, 0.850654,
0.688189, 0.499997, 0.525736, 0.276388, 0.850649, 0.447220, 0.162456, 0.499995, 0.850654,
0.162456, 0.499995, 0.850654, -0.425323, 0.309011, 0.850654, 0.000000, 0.000000, 1.000000,
0.162456, 0.499995, 0.850654, -0.262869, 0.809012, 0.525738, -0.425323, 0.309011, 0.850654,
-0.262869, 0.809012, 0.525738, -0.723607, 0.525725, 0.447220, -0.425323, 0.309011, 0.850654,
-0.425323, 0.309011, 0.850654, -0.425323, -0.309011, 0.850654, 0.000000, 0.000000, 1.000000,
-0.425323, 0.309011, 0.850654, -0.850648, 0.000000, 0.525736, -0.425323, -0.309011, 0.850654,
-0.850648, 0.000000, 0.525736, -0.723607, -0.525725, 0.447220, -0.425323, -0.309011, 0.850654,
-0.425323, -0.309011, 0.850654, 0.162456, -0.499995, 0.850654, 0.000000, 0.000000, 1.000000,
-0.425323, -0.309011, 0.850654, -0.262869, -0.809012, 0.525738, 0.162456, -0.499995, 0.850654,
-0.262869, -0.809012, 0.525738, 0.276388, -0.850649, 0.447220, 0.162456, -0.499995, 0.850654,
0.162456, -0.499995, 0.850654, 0.525730, 0.000000, 0.850652, 0.000000, 0.000000, 1.000000,
0.162456, -0.499995, 0.850654, 0.688189, -0.499997, 0.525736, 0.525730, 0.000000, 0.850652,
0.688189, -0.499997, 0.525736, 0.894426, 0.000000, 0.447216, 0.525730, 0.000000, 0.850652,
0.951058, 0.309013, 0.000000, 0.688189, 0.499997, 0.525736, 0.894426, 0.000000, 0.447216,
0.951058, 0.309013, 0.000000, 0.587786, 0.809017, 0.000000, 0.688189, 0.499997, 0.525736,
0.587786, 0.809017, 0.000000, 0.276388, 0.850649, 0.447220, 0.688189, 0.499997, 0.525736,
0.000000, 1.000000, 0.000000, -0.262869, 0.809012, 0.525738, 0.276388, 0.850649, 0.447220,
0.000000, 1.000000, 0.000000, -0.587786, 0.809017, 0.000000, -0.262869, 0.809012, 0.525738,
-0.587786, 0.809017, 0.000000, -0.723607, 0.525725, 0.447220, -0.262869, 0.809012, 0.525738,
-0.951058, 0.309013, 0.000000, -0.850648, 0.000000, 0.525736, -0.723607, 0.525725, 0.447220,
-0.951058, 0.309013, 0.000000, -0.951058, -0.309013, 0.000000, -0.850648, 0.000000, 0.525736,
-0.951058, -0.309013, 0.000000, -0.723607, -0.525725, 0.447220, -0.850648, 0.000000, 0.525736,
-0.587786, -0.809017, 0.000000, -0.262869, -0.809012, 0.525738, -0.723607, -0.525725, 0.447220,
-0.587786, -0.809017, 0.000000, 0.000000, -1.000000, 0.000000, -0.262869, -0.809012, 0.525738,
0.000000, -1.000000, 0.000000, 0.276388, -0.850649, 0.447220, -0.262869, -0.809012, 0.525738,
0.587786, -0.809017, 0.000000, 0.688189, -0.499997, 0.525736, 0.276388, -0.850649, 0.447220,
0.587786, -0.809017, 0.000000, 0.951058, -0.309013, 0.000000, 0.688189, -0.499997, 0.525736,
0.951058, -0.309013, 0.000000, 0.894426, 0.000000, 0.447216, 0.688189, -0.499997, 0.525736,
0.587786, 0.809017, 0.000000, 0.000000, 1.000000, 0.000000, 0.276388, 0.850649, 0.447220,
0.587786, 0.809017, 0.000000, 0.262869, 0.809012, -0.525738, 0.000000, 1.000000, 0.000000,
0.262869, 0.809012, -0.525738, -0.276388, 0.850649, -0.447220, 0.000000, 1.000000, 0.000000,
-0.587786, 0.809017, 0.000000, -0.951058, 0.309013, 0.000000, -0.723607, 0.525725, 0.447220,
-0.587786, 0.809017, 0.000000, -0.688189, 0.499997, -0.525736, -0.951058, 0.309013, 0.000000,
-0.688189, 0.499997, -0.525736, -0.894426, 0.000000, -0.447216, -0.951058, 0.309013, 0.000000,
-0.951058, -0.309013, 0.000000, -0.587786, -0.809017, 0.000000, -0.723607, -0.525725, 0.447220,
-0.951058, -0.309013, 0.000000, -0.688189, -0.499997, -0.525736, -0.587786, -0.809017, 0.000000,
-0.688189, -0.499997, -0.525736, -0.276388, -0.850649, -0.447220, -0.587786, -0.809017, 0.000000,
0.000000, -1.000000, 0.000000, 0.587786, -0.809017, 0.000000, 0.276388, -0.850649, 0.447220,
0.000000, -1.000000, 0.000000, 0.262869, -0.809012, -0.525738, 0.587786, -0.809017, 0.000000,
0.262869, -0.809012, -0.525738, 0.723607, -0.525725, -0.447220, 0.587786, -0.809017, 0.000000,
0.951058, -0.309013, 0.000000, 0.951058, 0.309013, 0.000000, 0.894426, 0.000000, 0.447216,
0.951058, -0.309013, 0.000000, 0.850648, 0.000000, -0.525736, 0.951058, 0.309013, 0.000000,
0.850648, 0.000000, -0.525736, 0.723607, 0.525725, -0.447220, 0.951058, 0.309013, 0.000000,
0.425323, 0.309011, -0.850654, 0.262869, 0.809012, -0.525738, 0.723607, 0.525725, -0.447220,
0.425323, 0.309011, -0.850654, -0.162456, 0.499995, -0.850654, 0.262869, 0.809012, -0.525738,
-0.162456, 0.499995, -0.850654, -0.276388, 0.850649, -0.447220, 0.262869, 0.809012, -0.525738,
-0.162456, 0.499995, -0.850654, -0.688189, 0.499997, -0.525736, -0.276388, 0.850649, -0.447220,
-0.162456, 0.499995, -0.850654, -0.525730, 0.000000, -0.850652, -0.688189, 0.499997, -0.525736,
-0.525730, 0.000000, -0.850652, -0.894426, 0.000000, -0.447216, -0.688189, 0.499997, -0.525736,
-0.525730, 0.000000, -0.850652, -0.688189, -0.499997, -0.525736, -0.894426, 0.000000, -0.447216,
-0.525730, 0.000000, -0.850652, -0.162456, -0.499995, -0.850654, -0.688189, -0.499997, -0.525736,
-0.162456, -0.499995, -0.850654, -0.276388, -0.850649, -0.447220, -0.688189, -0.499997, -0.525736,
0.850648, 0.000000, -0.525736, 0.425323, 0.309011, -0.850654, 0.723607, 0.525725, -0.447220,
0.850648, 0.000000, -0.525736, 0.425323, -0.309011, -0.850654, 0.425323, 0.309011, -0.850654,
0.425323, -0.309011, -0.850654, 0.000000, 0.000000, -1.000000, 0.425323, 0.309011, -0.850654,
-0.162456, -0.499995, -0.850654, 0.262869, -0.809012, -0.525738, -0.276388, -0.850649, -0.447220,
-0.162456, -0.499995, -0.850654, 0.425323, -0.309011, -0.850654, 0.262869, -0.809012, -0.525738,
0.425323, -0.309011, -0.850654, 0.723607, -0.525725, -0.447220, 0.262869, -0.809012, -0.525738,
];
const meshVerts = new Float32Array(verts);
const vertsLenght = meshVerts.length / 3;
gl.uniform1i(uLvertices, vertsLenght);
gl.pixelStorei(gl.UNPACK_ALIGNMENT, 1);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGB32F, vertsLenght, 1, 0, gl.RGB, gl.FLOAT, meshVerts);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
// mouse click
let mousePosition = [0, 0];
gl.canvas.addEventListener('mousemove', (e) => {
if (!e.buttons) return;
if (e.buttons == 1) mousePosition = [e.clientX * .01, e.clientY * .01];
}, !1);
// animation
const draw = (clock) => {
clock *= 0.001;
gl.viewport(0.0, 0.0, gl.drawingBufferWidth, gl.drawingBufferHeight);
gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.uniform1i(uLSr, 0);
gl.uniform1f(time_loc, clock);
gl.uniform2f(mouse_loc, mousePosition[0], mousePosition[1]);
gl.uniform2f(res_loc, width, height);
gl.drawArrays(gl.TRIANGLE_STRIP, 0, 6);
requestAnimationFrame(draw);
};
requestAnimationFrame(draw);
})()
和html文件：
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body>
<canvas id="c"></canvas>
<script type="text/javascript" src="main.js"></script>
</body>
</html>
我的问题是如何修改此代码以添加另一个对象？我是否需要将所有来自Blender的导出添加到verts变量并将其加载到着色器？如我所见，搅拌器出口保留有关对象位置的信息。
那灯呢？我该如何进行2遍渲染，首先计算几何形状，然后计算灯光？我从kronos https://github.com/tsherif/webgl2examples/blob/master/deferred.html中看到了这一点，但是有很多我不明白的地方。
我的目标是使用对象网格（随着搅拌器的导出）进行两次渲染渲染