视点游动生成光照贴图

上一文生成的光照贴图有两个缺点。其一稀疏点需要插值，插值后彩色不均。
其二物体遮挡有黑洞。
如果把入射光起点(视点)放在目标物体附近，然后移动光线，估计会形成一个密集的无黑洞的图像。
在平面上视点游动生成光照贴图

void 平面纹理生成(vector<Sphere_GLSL> &spheres, std::vector<Triangle_GLSL> &triangles, int Triangle_n0, int Triangle_n1) {
	double* image = new double[WIDTH * HEIGHT * 4];
	memset(image, 0.0, sizeof(double) * WIDTH * HEIGHT * 4);

	MaxMin t0 = 计算MaxMin(triangles, Triangle_n0);
	MaxMin t1 = 计算MaxMin(triangles, Triangle_n1);
	float xmax, xmin;
	float ymax, ymin;
	float zmax, zmin;
	xmin = min(t0.xmin, t1.xmin);
	xmax = max(t0.xmax, t1.xmax);
	ymin = min(t0.ymin, t1.ymin);
	ymax = max(t0.ymax, t1.ymax);
	zmin = min(t0.zmin, t1.zmin);
	zmax = max(t0.zmax, t1.zmax);
	string xyz = "xy";
	if (xmax == xmin)xyz = "yz";
	else if (ymax == ymin)xyz = "xz";
	else if (zmax == zmin)xyz = "xy";
	else {
		printf("err\n");
		return;
	}
	// 平面的基本参数
	float w, h, r, imin, imax, jmin, jmax;
	if (xyz == "xy") {
		w = xmax - xmin, h = ymax - ymin;
		r = zmin;
		imin = ymin, imax = ymax, jmin = xmin, jmax = xmax;
	}
	else if (xyz == "yz") {
		w = ymax - ymin, h = zmax - zmin;
		r = xmax;
		imin = zmin, imax = zmax, jmin = ymin, jmax = ymax;
	}
	else if (xyz == "xz") {
		w = xmax - xmin, h = zmax - zmin;
		r = ymin;
			jmin = xmin, jmax = xmax;
			imin = zmin, imax = zmax;
	}
	else {
		printf("err !!!\n");
		return;
	}

	// 参数化的步长
	float xStep = w / WIDTH;
	float yStep = h / HEIGHT;

	std::vector<Ray> Raywh;
	for (int k = 0; k < SAMPLE; k++)
	{
		printf("\r%d", k);
		double* p = image;
		Raywh.clear();
		//平面纹理生成
		//以平面大一圈的位置为起点,向平面垂线的方向为射线
		//--------------------------------------------


		
		// 遍历表面
		for (float i = imin; i < imax; i += yStep) {
			for (float j = jmin; j < jmax; j += xStep) {
				//printf("%.1f\n", j);

				// 计算面外的点坐标
				double x = j;
				double y = i;
				double z = r + 0.01f;
				vec3 eye = vec3(x, y, z);
				vec3 coord = vec3(x, y, r);
				float 移动 = 0.01f;
				if (r > 0)移动 = -0.01f;
				if (xyz == "xy") {
					x = j, y = i, z = r + 移动;
					// MSAA
					x += (randf() - 0.5f) / double(WIDTH);
					y += (randf() - 0.5f) / double(HEIGHT);
					eye = vec3(x, y, z);
					coord = vec3(x, y, r);

				}
				else if (xyz == "yz") {
					x = r + 移动, y = j, z = i;
					y += (randf() - 0.5f) / double(WIDTH);
					z += (randf() - 0.5f) / double(HEIGHT);
					eye = vec3(x, y, z);
					coord = vec3(r, y, z);
				}
				else if (xyz == "xz") {
					x = j, y = r + 移动, z = i;

					x += (randf() - 0.5f) / double(WIDTH);
					z += (randf() - 0.5f) / double(HEIGHT);
					eye = vec3(x, y, z);
					coord = vec3(x, r, z);

				}

				

				// 计算光线投射方向
				vec3 direction = normalize(coord - eye);

				Ray ray;
				ray.startPoint = eye;
				ray.direction = direction;
				Raywh.push_back(ray);

			}
		}

		//--------------------------------------------
		std::vector<vec4> color;
		// 路径追踪
		pathTracing_GLSL_TSn(Raywh, color);
		int nc = 0;
		for (int i = 0; i < HEIGHT; i++)
		{
			for (int j = 0; j < WIDTH; j++)
			{
				// 生成光线
				vec4 color0 = color[nc++];

				color0 *= BRIGHTNESS;

				*p += color0.x; p++;  // R 通道
				*p += color0.y; p++;  // G 通道
				*p += color0.z; p++;  // B 通道
				*p += color0.w; p++;  // A 通道
			}
		}

	}
	
	//imshow(image);
	{
		double* p = image;

		for (int i = 0; i < HEIGHT; i++)
		{
			for (int j = 0; j < WIDTH; j++)
			{

				*p = clamp(pow(*p, 1.0f / 2.2f) * 255, 0.0, 255.0); p++; // R 通道
				*p = clamp(pow(*p, 1.0f / 2.2f) * 255, 0.0, 255.0); p++; // G 通道
				*p = clamp(pow(*p, 1.0f / 2.2f) * 255, 0.0, 255.0); p++; // B 通道
				*p = clamp(pow(*p, 1.0f / 2.2f) * 255, 0.0, 255.0); p++; // A 通道
			}
		}
	}
	char filename[256];
	sprintf_s(filename, "triangle0%d%d.png", Triangle_n0, Triangle_n1);
	imSave(image, WIDTH, HEIGHT, filename);


	delete image;
}

对比:左边是前面生成的，右边是这次生成的。
 

然后运行代码

球上要怎么处理，还没有想好，以后再写吧。