原文:HLSL效果框架-多光源效果

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高级着色器语言(HLSL)难就难在它是运行在GPU,CPU上的,编写和调试都很麻烦.

用效果框架简化了很多操作,先列出着色器的代码,重点部分都用中文注释了

着色器语言文件为:,代码为:

//着色器处理未知数量光源数目 未知光源种类 的 混合效果
//HLSL里一共支持256个float4,一个int最后也转成float4,float4x3和float3x3占内存一样,最终都变成float4
//因为HLSL的限制条件非常零散也非常多,所以,用起来还是很吃力的,在不懂的情况下,
//最终指令不能超过500多条貌似,运行在显卡中程序,所以能省则省,能精简则精简!!!

//
//结构体 注意:为了优化结构,把一些相关参数整合到了一起
//
struct PointLight	//点光源 结构
{
	float4 Diffuse;		//漫反射的颜色r,g,b,a
	float4 Specular;	//镜面高光的颜色r,g,b,a
	float4 Position;	//光源位置x,y,z,w没用到
	float4 RangeAttenuation;//范围,恒定衰减,光强,二次衰减
};

struct DirectLight	//方向光 结构
{
	float4 Diffuse;		//漫反射的颜色r,g,b,a
	float4 Specular;	//镜面高光的颜色r,g,b,a
	float4 Direction;	//方向x,y,z,高光
};

struct SpotLight	//聚光灯 结构
{
	float4 Diffuse;		//漫反射的颜色r,g,b,a
	float4 Specular;	//镜面高光的颜色r,g,b,a
	float4 Position;	//光源位置x,y,z,w没用到
	float4 Direction;	//方向x,y,z,w没用到
	float4 RangeAttenuation;//范围,恒定衰减,光强,二次衰减
	float4 FalloffThetaPhi;	//从内锥到外锥之间的强度衰减,y没用到,内锥的弧度,外锥的弧度
};

//接收光源的数量
int g_NumPLs;	//程序里定义了几个点光源?
int g_NumDLs;	//程序里定义了几个方向光源?
int g_NumSLs;	//程序里定义了几个方向光源?

PointLight		g_PLs[10];	//定义最多支持10个点光源
DirectLight		g_DLs[10];	//定义最多支持10个方向光源
SpotLight		g_SLs[10];	//定义最多支持10个聚光灯光源

//环境光(对于多灯光的场合，对每一个灯光循环进行这些运算（环境光除外）)
//最后加上环境光(假设只有一个环境光)

matrix g_WorldMatrix;//世界矩阵
float4 g_ViewPos;//观察点(相机)
matrix WVPMatrix;	//世界-观察-投影矩阵

float AmbAmount;	//环境光的强弱程度,介于0-1之间
float4 AmbCol = { 1.0f, 1.0f, 1.0f, 1.0f };//环境光的颜色,默认白色

//--------------------------------------------------------------------------
//				顶点着色器(注意看下面,我把顶点着色器的输出顶点位置和法线,当作像素着色器的输入了!!!
//							TEXCOORD这类寄存器也没啥用,用来保存顶点和法线数据最合适不过了,最多好像是15个)
//--------------------------------------------------------------------------
struct VS_INPUT		//输入结构
{
	float4 position : POSITION;//输入:坐标
	float3 normal : NORMAL;	//输入:法线
};
struct VS_OUTPUT	//输出结构
{
	float4 position : POSITION;
	float4 vtpos : TEXCOORD0;//传入像素着色器用,TEXCOORD表示寄存器名字,(实际上保存的数据当像素着色器的输入坐标用,用TEXCOORD,一方面是多,二方面没啥用)
	float3 normal : TEXCOORD1;
};

VS_OUTPUT VS_Main(VS_INPUT input)
{
	VS_OUTPUT output = (VS_OUTPUT)0;
	output.vtpos = input.position;//模型本地空间坐标
	output.position = mul(input.position, WVPMatrix);//输出:世界-观察-投影变幻后的坐标
	output.normal = input.normal;
	return output;
}

//--------------------------------------------------------------------------
//				像素着色器(COLOR0是必须输出的,其他的可作任何用途)
//--------------------------------------------------------------------------
struct PS_INPUT		//输入
{
	float4 vtpos : TEXCOORD0;//顶点位置(接受顶点着色器的输出,要对应)
	float3 normal : TEXCOORD1;
};
struct PS_OUTPUT	//输出像素颜色
{
	float4 Color : COLOR0;	//像素着色器最终输出计算好的颜色
};
PS_OUTPUT PS_Main(PS_INPUT input)
{
	PS_OUTPUT output = (PS_OUTPUT)0;

	float4 worldpos = mul(input.vtpos, g_WorldMatrix);//顶点在世界空间中的坐标,即乘以世界矩阵
	float4 colRes;//用于保存最终的颜色 = E环境光+自身光+E(点光+方向光+聚光); 其中点,方向,聚光 又包含漫反射,镜面反射
	float4 ambient = { 0.0f, 0.0f, 0.0f, 1.0f };//总环境光
	float4 self = { 0.0f, 0.0f, 0.0f, 1.0f };//自发光
	float4 diffuse = { 0.0f, 0.0f, 0.0f, 1.0f };//总漫反射光
	float4 specular = { 0.0f, 0.0f, 0.0f, 1.0f };//总镜面反射

	ambient = AmbCol * AmbAmount;//求出环境光

	for (int i = 0; i < g_NumPLs; i++)//点光源
	{
		float3 dirSize = input.vtpos.xyz - g_PLs[i].Position.xyz;//光源到顶点的方向和大小.光源→顶点pos
		float distance = length(dirSize);//距离
		float3 dir = normalize(dirSize);//单位化方向
		if (distance < g_PLs[i].RangeAttenuation.x)//顶点在灯光范围内
		{
			//求出漫反射
			float difusefactor = dot(dir.xyz, input.normal.xyz);
			if (difusefactor < 0)
			{
				difusefactor = 0;
			}
			float distanceDec = 1.0f - 1.0f / g_PLs[i].RangeAttenuation.x * distance;
			//漫反射 = diffuse*漫反射因子*距离衰减
			diffuse.xyz += g_PLs[i].Diffuse.xyz * difusefactor * distanceDec;//最后要乘以材质的吸收系数(这里没乘)

			//下面求镜面反射(镜面反射的算法自己去百度找吧...)
			float3 DirectionToView = normalize(worldpos.xyz - g_ViewPos.xyz);  //(同在世界空间中!)
			float3 VectorToLight = normalize(input.vtpos.xyz - g_PLs[i].Position.xyz);
				//计算反射光
			float3 reflectanceRay = 2 * dot(input.normal.xyz, VectorToLight.xyz)*input.normal.xyz - VectorToLight.xyz;
			float specfactor = pow(abs(dot(reflectanceRay, DirectionToView)), g_PLs[i].RangeAttenuation.z);
				//镜面光累加
			specular.xyz += g_PLs[i].Specular.xyz * specfactor;//最后要乘以材质的吸收系数(这里没乘)
		}
		//else在光线外,无此光照影响
	}
	for (int j = 0; j < g_NumDLs; j++)//方向光源
	{
		//漫反射
		float3 dir = normalize(g_DLs[j].Direction.xyz);//单位化方向(光的方向)
		float difusefactor = dot(dir.xyz, input.normal.xyz);
		if (difusefactor < 0)
		{
			difusefactor = 0;
		}
		diffuse.xyz += g_DLs[j].Diffuse.xyz * difusefactor;//最后要乘以材质的吸收系数(这里没乘)

		//镜面反射
		float3 DirectionToView = normalize(worldpos.xyz - g_ViewPos.xyz);//观察点→顶点  (同在世界空间中!)
		//dir 已有
			//计算反射光
		float3 reflectanceRay = 2 * dot(input.normal.xyz, dir.xyz)*input.normal.xyz - dir.xyz;
		float specfactor = pow(abs(dot(reflectanceRay, DirectionToView)), g_DLs[j].Direction.w);
			//镜面光累加
		specular.xyz += g_DLs[j].Specular.xyz * specfactor;//最后要乘以材质的吸收系数(这里没乘)
	}

	for (int k = 0; k < g_NumSLs; k++)//聚光灯
	{
		float disdec = 0.0f;//距离衰减
		float raddec = 0.0f;//角度衰减

		float distance = length(g_SLs[k].Position.xyz - worldpos.xyz);//光源到顶点的距离
		float3 xconeDirection = normalize(g_SLs[k].Direction.xyz);//聚光灯方向
		float3 ltvdir = normalize(g_SLs[k].Position.xyz - worldpos.xyz);//光到顶点的方向
		float cosx = abs(dot(xconeDirection, ltvdir));//夹角的余弦值

		float cosPhi = cos(g_SLs[k].FalloffThetaPhi.w / 2.0f);
		float cosTheta = cos(g_SLs[k].FalloffThetaPhi.z / 2.0f);

		//距离衰减因子
		float sss = 1.0f / g_SLs[k].RangeAttenuation.x;

		if (cosx>cosTheta)//本影(角度衰减: 不衰减)
		{
			raddec = 1.0f;

			if (distance*cosx <g_SLs[k].RangeAttenuation.x)//在射程范围内
			{
				disdec = 1.0f - 1.0f / g_SLs[k].RangeAttenuation.x*distance*cosx;//距离衰减(线性衰减)
			}
		}

		if (cosx < cosTheta)//本影外(角度衰减: 急剧衰减 )
		{
			float v1 = cosx - cosPhi;
			float v2 = cosTheta - cosPhi;
			float v3 = v1 / v2;
			raddec = pow(abs(v3), g_SLs[k].FalloffThetaPhi.x);

			if (distance*cosx <g_SLs[k].RangeAttenuation.x)//在射程范围内(无光)
			{
				disdec = 1.0f - 1.0f / g_SLs[k].RangeAttenuation.x*distance*cosx; //距离衰减(线性衰减)
			}
		}

		if (cosx<cosPhi)//光锥外
		{
			raddec = 0.0f;
		}

		//计算漫反射
		float difusefactor = dot(ltvdir.xyz, input.normal.xyz);
		if (difusefactor < 0.0f)
		{
			difusefactor = 0.0f;
		}
		diffuse.xyz += g_SLs[k].Diffuse.xyz * raddec * disdec * difusefactor;//最后要乘以材质的吸收系数(这里没乘)

		//计算镜面反射
		float3 DirectionToView = normalize(worldpos.xyz - g_ViewPos.xyz);//观察点→顶点  (同在世界空间中!)
		float3 VectorToLight = normalize(input.vtpos.xyz - g_SLs[k].Position.xyz);
			//计算反射光
		float3 reflectanceRay = 2 * dot(input.normal.xyz, VectorToLight.xyz)*input.normal.xyz - VectorToLight.xyz;
		float specfactor = pow(abs(dot(reflectanceRay, DirectionToView)), g_SLs[k].RangeAttenuation.z);
			//镜面光累加
		specular.xyz += g_SLs[k].Specular.xyz * raddec * disdec * specfactor;//最后要乘以材质的吸收系数(这里没乘)
	}

	output.Color.w = 1.0f;//因为output被初始化为(PS_OUTPUT)0,w也初始化为0了.
	output.Color.xyz = ambient.xyz + self.xyz + diffuse.xyz + specular.xyz;//把所有种类的光都累加起来
	return output;
}

//--------------------------------------------------------------------------
//				框架效果
//--------------------------------------------------------------------------
technique MulLights
{
	pass P0
	{
		vertexShader = compile vs_3_0 VS_Main();//顶点着色器
		pixelshader = compile ps_3_0 PS_Main();//像素着色器
	}
}

值得注意的是,环境光也可以有好几个(这里假设只有一个),另外,光照的最终叠加效果公式为:

最终光照颜色 =?所有的环境光 *?材质吸收指数?+?自发光 + (点光源 +?方向光源+聚光灯) * (漫反射 +?镜面反射) *材质吸收指数????????

(自己推算的公式,可能有误,欢迎批评指出)

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然后是应用程序中的代码:

变量定义:

D3DXMATRIX m_ProjMatrix;?//投影矩阵

?D3DXMATRIX m_ViewMatrix;?//观察矩阵

?//四个模型

?ID3DXMesh*????m_Meshes[4];

?D3DXMATRIX????m_WorldMatrices[4];

?D3DXVECTOR4????m_MeshColors[4];

?D3DMATERIAL9???m_Material;

?//点光源

?PointLight????m_PointLight[10];

?DirectLight???m_DirectLight[10];

?SpotLight????m_SpotLight[10];

?//-----------顶点着色器相关------------------

?D3DXHANDLE???m_WVPMatrixHandle;//世界-观察-投影矩阵句柄

?//-----------效果框架-----------------

?ID3DXEffect*???m_NLightEffect = 0;

?//-----------------句柄------------------------

?D3DXHANDLE????m_TecniMulLightsHandle = 0;?//技术句柄

?D3DXHANDLE????m_AmbAmountHandle = 0;??//环境光系数句柄

??//各种光源句柄

?D3DXHANDLE????m_PointLHandle = 0;???//点光源句柄

?D3DXHANDLE????m_DirectLightHandle = 0;?//方向光句柄

?D3DXHANDLE????m_SpotLightHandle = 0;??//聚光灯句柄

??//各种光源数量句柄

?D3DXHANDLE????m_NumPointLightHandle = 0;?//点光源个数句柄

?D3DXHANDLE????m_NumDirectLightHandle = 0;?//方向光个数句柄

?D3DXHANDLE????m_NumSpotLightHandle = 0;?//聚光灯个数句柄

?D3DXHANDLE????m_ViewPosHandle = 0;??//观察点句柄

?D3DXHANDLE????m_WorldMatrixHandle = 0;?//世界矩阵句柄

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#define MESH_TEAPOT		0
#define MESH_SPHERE		1
#define MESH_TORUS		2
#define MESH_CYLINDER	3

typedef D3DXVECTOR4 float4;	//这里typedef成float4,就能与着色器里面一致,不需要改代码了!

struct PointLight
{
	float4 Diffuse;		//漫反射的颜色
	float4 Specular;	//镜面高光的颜色
	float4 Position;	//光源位置
	float4 RangeAttenuation;//范围,恒定衰减,镜面光强弱,二次衰减
};

struct DirectLight
{
	float4 Diffuse;		//漫反射的颜色
	float4 Specular;	//镜面高光的颜色
	float4 DirectionPow;	//方向x,y,z,高光
};

struct SpotLight
{
	float4 Diffuse;		//漫反射的颜色
	float4 Specular;	//镜面高光的颜色
	float4 Position;	//光源位置
	float4 Direction;	//方向
	float4 RangeAttenuation;//范围,恒定衰减,镜面光强弱,二次衰减
	float4 FalloffThetaPhi;	//从内锥到外锥之间的强度衰减,NULL,内锥的弧度,外锥的弧度
};

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//setup: main函数中调用一次
	void Setup()
	{
		HRESULT hr = 0;

		//创建模型们: 茶壶 圆球 圆环 圆桶
		D3DXCreateTeapot(m_d3dDevice->GetD3DDevice(), &m_Meshes[MESH_TEAPOT], NULL);
		D3DXCreateSphere(m_d3dDevice->GetD3DDevice(), 1.0f, 20, 20, &m_Meshes[MESH_SPHERE], NULL);
		D3DXCreateTorus(m_d3dDevice->GetD3DDevice(), 0.5f, 1.0f, 20, 20, &m_Meshes[MESH_TORUS], NULL);
		D3DXCreateCylinder(m_d3dDevice->GetD3DDevice(), 0.5f, 0.5f, 2.0f, 20, 20, &m_Meshes[MESH_CYLINDER], NULL);
		//模型们的在世界中的矩阵:
		D3DXMatrixTranslation(&m_WorldMatrices[MESH_TEAPOT], 0.0f, 2.0f, 0.0f);
		D3DXMatrixTranslation(&m_WorldMatrices[MESH_SPHERE], 0.0f, -2.0f, 0.0f);
		D3DXMatrixTranslation(&m_WorldMatrices[MESH_TORUS], -3.0f, 0.0f, 0.0f);
		D3DXMatrixTranslation(&m_WorldMatrices[MESH_CYLINDER], 3.0f, 0.0f, 0.0f);
		//模型们的颜色:
		m_MeshColors[MESH_TEAPOT] = D3DXVECTOR4(1.0f, 1.0f, 1.0f, 1.0f);
		m_MeshColors[MESH_SPHERE] = D3DXVECTOR4(1.0f, 1.0f, 1.0f, 1.0f);
		m_MeshColors[MESH_TORUS] = D3DXVECTOR4(1.0f, 1.0f, 1.0f, 1.0f);
		m_MeshColors[MESH_CYLINDER] = D3DXVECTOR4(1.0f, 1.0f, 1.0f, 1.0f);

		//
		//创建两个点光源
			//m_PointLight[0]
		m_PointLight[0].Diffuse = { 1.0f, 0.0f, 0.0f, 1.0f };//Diffuse
		m_PointLight[0].Specular = { 1.0f, 1.0f, 1.0f, 1.0f };//Specular
		m_PointLight[0].Position = { -6.0f, 2.0f, 2.0f, 0.0f };//Position
		m_PointLight[0].RangeAttenuation = { 15.0f, 1.0f, 50.0f, 0.0f };//Range,Attenuation0,镜面光强弱,Attenuation2
			//m_PointLight[1]
		m_PointLight[1].Diffuse = { 0.0f, 1.0f, 0.0f, 1.0f };
		m_PointLight[1].Specular = { 1.0f, 1.0f, 1.0f, 1.0f };
		m_PointLight[1].Position = { 6.0f, 2.0f, 3.0f, 0.0f };
		m_PointLight[1].RangeAttenuation = { 15.0f, 0.8f, 50.0f, 0.0f };
		//创建一个方向光
			//m_DirectLight[0]
		m_DirectLight[0].Diffuse = { 0.5f, 0.5f, 0.5f, 1.0f };
		m_DirectLight[0].Specular = { 0.5f, 0.5f, 0.5f, 1.0f };
		m_DirectLight[0].DirectionPow = { 0.0f, 0.0f, -1.0f, 10.0f };//(z轴正方向)
		//创建一个聚光灯
			//m_SpotLight[0]
		m_SpotLight[0].Diffuse = { 1.0f, 1.0f, 1.0f, 1.0f };
		m_SpotLight[0].Specular = { 1.0f, 1.0f, 1.0f, 1.0f };
		m_SpotLight[0].Position = { 0.0f, 1.8f, -5.0f, 0.0f };
		m_SpotLight[0].Direction = { 0.0f, 0.0f, 1.0f, 0.0f };
		m_SpotLight[0].FalloffThetaPhi = { 3.5f, 0.0f, 0.04f, 0.18f };//衰减,-,内角(弧度半角),外角(弧度半角)
		m_SpotLight[0].RangeAttenuation = { 10.0f, 0.0f, 20.0f, 0.0f };//范围,衰减1,高光,衰减2

		ID3DXBuffer* errorBuffer = 0;
		hr = D3DXCreateEffectFromFile(m_d3dDevice->GetD3DDevice(),
			L"D:\\nlight.fx",
			0,
			0,
			D3DXSHADER_ENABLE_BACKWARDS_COMPATIBILITY,
			0,
			&m_NLightEffect,
			&errorBuffer);
		// 输出错误信息:
		if (errorBuffer)
		{
			string str = (char*)errorBuffer->GetBufferPointer();
			MessageBox(NULL, Common::StringToWString(str).c_str(), L"ERROR", MB_OK);
			//safe_release<ID3DXBuffer*>(error_buffer);
		}
		if (FAILED(hr))
		{
			MessageBox(NULL, L"D3DXCreateEffectFromFile() - FAILED", L"ERROR", MB_OK);
		} 

		//获取hlsl中常量句柄
			//得到技术technique MulLights的句柄
		m_TecniMulLightsHandle = m_NLightEffect->GetTechniqueByName("MulLights");
			//各种光源的个数
		m_NumPointLightHandle = m_NLightEffect->GetParameterByName(NULL, "g_NumPLs");
		m_NumDirectLightHandle = m_NLightEffect->GetParameterByName(NULL, "g_NumDLs");
		m_NumSpotLightHandle = m_NLightEffect->GetParameterByName(NULL, "g_NumSLs");
			//获取光源种类的句柄
		m_AmbAmountHandle = m_NLightEffect->GetParameterByName(NULL, "AmbAmount");//环境光因子句柄
		m_PointLHandle = m_NLightEffect->GetParameterByName(NULL, "g_PLs");//点光源句柄
		m_DirectLightHandle = m_NLightEffect->GetParameterByName(NULL, "g_DLs");//方向光句柄
		m_SpotLightHandle = m_NLightEffect->GetParameterByName(NULL, "g_SLs");//聚光灯句柄
			//获取观察点,矩阵句柄
		m_ViewPosHandle = m_NLightEffect->GetParameterByName(NULL, "g_ViewPos");
		m_WorldMatrixHandle = m_NLightEffect->GetParameterByName(NULL, "g_WorldMatrix");
		m_WVPMatrixHandle = m_NLightEffect->GetParameterByName(NULL, "WVPMatrix");//世界观察投影矩阵

		//设置常量句柄
			//传光源数据进去
		m_NLightEffect->SetRawValue(m_PointLHandle, m_PointLight, 0,sizeof(PointLight)*2);//传点光源
		m_NLightEffect->SetRawValue(m_DirectLightHandle, m_DirectLight, 0, sizeof(DirectLight)* 1);//传方向光
		m_NLightEffect->SetRawValue(m_SpotLightHandle, m_SpotLight, 0, sizeof(SpotLight)* 1);//传聚光灯

		m_NLightEffect->SetFloat(m_AmbAmountHandle, 0.0f);
		m_NLightEffect->SetInt(m_NumPointLightHandle, 2);//点光源数量:2 (调节个数可方便调试)
		m_NLightEffect->SetInt(m_NumDirectLightHandle, 1);//方向光数量:1
		m_NLightEffect->SetInt(m_NumSpotLightHandle, 1);//聚光灯数量:1

		//设置投影矩阵
		RECT rt;
		GetClientRect(Application::GetInstance()->GetWnd(), &rt);
		D3DXMatrixPerspectiveFovLH(&m_ProjMatrix, D3DX_PI / 4.0f, (float)rt.right / rt.bottom, 1.0f, 1000.0f);

		//暂时未设置纹理
		m_d3dDevice->GetD3DDevice()->SetRenderState(D3DRS_LIGHTING, false);//关闭灯光,即不用固定管线
	}

?

	//display: 在消息循环中调用,时时更新
	void Display(float timeDelta)
	{
		static float angle = (3.0f * D3DX_PI) / 2.0f;
		static float height = 0.0f;

		if (GetAsyncKeyState(VK_LEFT) & 0x8000f)
			angle -= 0.5f * timeDelta;

		if (GetAsyncKeyState(VK_RIGHT) & 0x8000f)
			angle += 0.5f * timeDelta;

		if (GetAsyncKeyState(VK_UP) & 0x8000f)
			height += 5.0f * timeDelta;

		if (GetAsyncKeyState(VK_DOWN) & 0x8000f)
			height -= 5.0f * timeDelta;

		//求出观察矩阵
		D3DXVECTOR3 position(cosf(angle) * 7.0f, height, sinf(angle) * 7.0f);
		D3DXVECTOR3 target(0.0f, 0.0f, 0.0f);
		D3DXVECTOR3 up(0.0f, 1.0f, 0.0f);
		D3DXMatrixLookAtLH(&m_ViewMatrix, &position, &target, &up);
		D3DXVECTOR4 vps = { cosf(angle) * 7.0f, height, sinf(angle) * 7.0f, 0.0f };
		m_NLightEffect->SetVector(m_ViewPosHandle, &vps);

		// render now
		m_d3dDevice->GetD3DDevice()->Clear(0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, 0x99999999, 1.0f, 0);
		m_d3dDevice->GetD3DDevice()->BeginScene();

		//设置技术
		m_NLightEffect->SetTechnique(m_TecniMulLightsHandle);

		D3DXMATRIX WVPMatrix;

		for (int i = 0; i < 4; i++)
		{
			WVPMatrix = m_WorldMatrices[i] * m_ViewMatrix * m_ProjMatrix;

			m_NLightEffect->SetMatrix(m_WorldMatrixHandle, &m_WorldMatrices[i]);
			m_NLightEffect->SetMatrix(m_WVPMatrixHandle, &WVPMatrix);
			UINT numPass = 0;
			m_NLightEffect->Begin(&numPass, 0);
			for (UINT j = 0; j < numPass; ++j)
			{
				//开始过程
				m_NLightEffect->BeginPass(j);	//在begin和end中间不建议设置着色器变量
				m_Meshes[i]->DrawSubset(0);
				//结束过程
				m_NLightEffect->EndPass();
			}
			//结束使用技术
			m_NLightEffect->End();
		}
		m_d3dDevice->GetD3DDevice()->EndScene();
		m_d3dDevice->GetD3DDevice()->Present(NULL, NULL, NULL, NULL);
	}

测试一: 1个点光源:

发现了一个错误!!!:黑色的地方没有光照,居然也有镜面反射了,oh,shit,网上的算法也不严谨嘛...

解决方法:稍微一思考,有光的地方才有镜面反射对吧?怎么样才有光? 就是光线方向和面法线的夹角要大于0,

即difusefactor = dot(光线,面法线)>0.0f; 即difusefactor>0.0f,所以,HLSL里在计算镜面光的时候多加一个

判断:

//镜面反射算法

???if (difusefactor>0.0f)?//只有有光照到的地方才有镜面反射!!!

???{

????float3 DirectionToView = normalize(worldpos.xyz - g_ViewPos.xyz);? //(同在世界空间中!)

?????float3 VectorToLight = normalize(input.vtpos.xyz - g_PLs[i].Position.xyz);

?????//计算反射光

?????float3 reflectanceRay = 2 * dot(input.normal.xyz, VectorToLight.xyz)*input.normal.xyz - VectorToLight.xyz;

?????float specfactor = pow(abs(dot(reflectanceRay, DirectionToView)), g_PLs[i].RangeAttenuation.z);

????//镜面光累加

????specular.xyz += g_PLs[i].Specular.xyz * specfactor;//最后要乘以材质的吸收系数(这里没乘)

???}??

(下面的效果图都没有修改这一个错误,自行修改)

测试二:?两个点光源:

测试三:?方向光:

测试四:聚光灯:

测试五:火力全开:

(亮瞎眼了~...)

??

??

原文地址：https://www.cnblogs.com/lonelyxmas/p/10807300.html