DirectX 10 教程21:高光映射

原文地址:Tutorial 21: Specular Mapping(http://www.rastertek.com/dx10tut21.html)。

源代码下载:dx10tut21.zip

本教程介绍如何实现高光映射以及如何将它和法线映射整合起来。

本教程的代码是教程bump map和教程specular lighting的组合。

高光映射就是通过查询一张纹理的alpha通道获取每个像素的高光强度。

例如我们使用的颜色纹理如下图所示:

颜色纹理

法线贴图如下图所示:

法线贴图

我们接下来要介绍的高光映射所使用的高光贴图如下图所示:

高光贴图

我们使用的是这张高光贴图的灰度确定每个像素的高光强度。这张贴图让纹理的每个小方块都有自己的高光强度,而且还使用了法线映射,最终获得的效果如下图所示:

最终效果

框架

相对于上一个教程,框架进行了微调,新的SpecMapShaderClass代替了BumpMapShaderClass。

框架

首先看一下specular map HLSL shader的代码:

Specmap.fx

////////////////////////////////////////////////////////////////////////////////
// Filename: specmap.fx
////////////////////////////////////////////////////////////////////////////////


/////////////
// GLOBALS //
/////////////
matrix worldMatrix;
matrix viewMatrix;
matrix projectionMatrix;

specular map shader需要包含三张纹理的纹理数组,第一张为颜色纹理,第二张为法线贴图,第三张为高光贴图。

Texture2D shaderTextures[3];
float4 diffuseColor;
float3 lightDirection;

因为需要用到高光,所以需要相机位置、高光颜色和高光指数的信息。

float3 cameraPosition;
float4 specularColor;
float specularPower;


///////////////////
// SAMPLE STATES //
///////////////////
SamplerState SampleType
{
    Filter = MIN_MAG_MIP_LINEAR;
    AddressU = Wrap;
    AddressV = Wrap;
};


//////////////
// TYPEDEFS //
//////////////
struct VertexInputType
{
    float4 position : POSITION;
    float2 tex : TEXCOORD0;
	float3 normal : NORMAL;
	float3 tangent : TANGENT;
	float3 binormal : BINORMAL;
};

PixelInputType新添了viewDirection用于高光运算。

struct PixelInputType
{
    float4 position : SV_POSITION;
    float2 tex : TEXCOORD0;
   	float3 normal : NORMAL;
   	float3 tangent : TANGENT;
    float3 binormal : BINORMAL;
    float3 viewDirection : TEXCOORD1;
};


////////////////////////////////////////////////////////////////////////////////
// Vertex Shader
////////////////////////////////////////////////////////////////////////////////
PixelInputType SpecMapVertexShader(VertexInputType input)
{
    PixelInputType output;
    float4 worldPosition;

    
	// Change the position vector to be 4 units for proper matrix calculations.
    input.position.w = 1.0f;

	// Calculate the position of the vertex against the world, view, and projection matrices.
    output.position = mul(input.position, worldMatrix);
    output.position = mul(output.position, viewMatrix);
    output.position = mul(output.position, projectionMatrix);
    
	// Store the texture coordinates for the pixel shader.
    output.tex = input.tex;
    
	// Calculate the normal vector against the world matrix only and then normalize the final value.
	output.normal = mul(input.normal, (float3x3)worldMatrix);
	output.normal = normalize(output.normal);

	// Calculate the tangent vector against the world matrix only and then normalize the final value.
	output.tangent = mul(input.tangent, (float3x3)worldMatrix);
	output.tangent = normalize(output.tangent);

	// Calculate the binormal vector against the world matrix only and then normalize the final value.
    output.binormal = mul(input.binormal, (float3x3)worldMatrix);
	output.binormal = normalize(output.binormal);

要处理镜面高光,我们计算观察方向,并将它传递到像素着色器中。

	// Calculate the position of the vertex in the world.
    worldPosition = mul(input.position, worldMatrix);

    // Determine the viewing direction based on the position of the camera and the position of the vertex in the world.
    output.viewDirection = cameraPosition.xyz - worldPosition.xyz;
	
    // Normalize the viewing direction vector.
    output.viewDirection = normalize(output.viewDirection);

	return output;
}



////////////////////////////////////////////////////////////////////////////////
// Pixel Shader
////////////////////////////////////////////////////////////////////////////////
float4 SpecMapPixelShader(PixelInputType input) : SV_Target
{
	float4 textureColor;
    float4 bumpMap;
    float3 bumpNormal;
	float3 lightDir;
	float lightIntensity;
	float4 color;
	float4 specularIntensity;
	float3 reflection;
	float4 specular;

第一部分的代码是常规的法线贴图shader代码。

	// Sample the texture pixel at this location.
	textureColor = shaderTextures[0].Sample(SampleType, input.tex);
	
    // Sample the pixel in the bump map.
    bumpMap = shaderTextures[1].Sample(SampleType, input.tex);

    // Expand the range of the normal value from (0, +1) to (-1, +1).
    bumpMap = (bumpMap * 2.0f) - 1.0f;

    // Calculate the normal from the data in the bump map.
    bumpNormal = input.normal + bumpMap.x * input.tangent + bumpMap.y * input.binormal;
	
    // Normalize the resulting bump normal.
    bumpNormal = normalize(bumpNormal);

	// Invert the light direction for calculations.
	lightDir = -lightDirection;

	// Calculate the amount of light on this pixel based on the bump map normal value.
	lightIntensity = saturate(dot(bumpNormal, lightDir));

	// Determine the final diffuse color based on the diffuse color and the amount of light intensity.
	color = saturate(diffuseColor * lightIntensity);

	// Combine the final bump light color with the texture color.
	color = color * textureColor;

如果光照强度大于零,则需要继续计算镜面高光。

	if(lightIntensity > 0.0f)
	{

下面的代码就是从高光贴图中采样光照强度的操作。

		// Sample the pixel from the specular map texture.
		specularIntensity = shaderTextures[2].Sample(SampleType, input.tex);

在反射计算中,我们使用的是法线贴图的法线而不是常规的顶点法线。

		// Calculate the reflection vector based on the light intensity, normal vector, and light direction.
		reflection = normalize(2 * lightIntensity * bumpNormal - lightDir); 

		// Determine the amount of specular light based on the reflection vector, viewing direction, and specular power.
		specular = pow(saturate(dot(reflection, input.viewDirection)), specularPower);

有了高光颜色,我们再将它乘以从高光贴图获取的高光强度,就获得了最终的输出颜色。

		// Use the specular map to determine the intensity of specular light at this pixel.
		specular = specular * specularIntensity;
		
		// Add the specular component last to the output color.
	    color = saturate(color + specular);
	}
	
	return color;
}


////////////////////////////////////////////////////////////////////////////////
// Technique
////////////////////////////////////////////////////////////////////////////////
technique10 SpecMapTechnique
{
    pass pass0
    {
        SetVertexShader(CompileShader(vs_4_0, SpecMapVertexShader()));
        SetPixelShader(CompileShader(ps_4_0, SpecMapPixelShader()));
        SetGeometryShader(NULL);
    }
}

Specmapshaderclass.h

SpecMapShaderClass只是上一个教程中的BumpMapShaderClass的改编版本。

////////////////////////////////////////////////////////////////////////////////
// Filename: specmapshaderclass.h
////////////////////////////////////////////////////////////////////////////////
#ifndef _SPECMAPSHADERCLASS_H_
#define _SPECMAPSHADERCLASS_H_


//////////////
// INCLUDES //
//////////////
#include <d3d10.h>
#include <d3dx10.h>
#include <fstream>
using namespace std;


////////////////////////////////////////////////////////////////////////////////
// Class name: SpecMapShaderClass
////////////////////////////////////////////////////////////////////////////////
class SpecMapShaderClass
{
public:
	SpecMapShaderClass();
	SpecMapShaderClass(const SpecMapShaderClass&);
	~SpecMapShaderClass();

	bool Initialize(ID3D10Device*, HWND);
	void Shutdown();
	void Render(ID3D10Device*, int, D3DXMATRIX, D3DXMATRIX, D3DXMATRIX, ID3D10ShaderResourceView**, D3DXVECTOR3, D3DXVECTOR4, 
				D3DXVECTOR3, D3DXVECTOR4, float);

private:
	bool InitializeShader(ID3D10Device*, HWND, WCHAR*);
	void ShutdownShader();
	void OutputShaderErrorMessage(ID3D10Blob*, HWND, WCHAR*);

	void SetShaderParameters(D3DXMATRIX, D3DXMATRIX, D3DXMATRIX, ID3D10ShaderResourceView**, D3DXVECTOR3, D3DXVECTOR4, 
							 D3DXVECTOR3, D3DXVECTOR4, float);
	void RenderShader(ID3D10Device*, int);

private:
	ID3D10Effect* m_effect;
	ID3D10EffectTechnique* m_technique;
	ID3D10InputLayout* m_layout;

	ID3D10EffectMatrixVariable* m_worldMatrixPtr;
	ID3D10EffectMatrixVariable* m_viewMatrixPtr;
	ID3D10EffectMatrixVariable* m_projectionMatrixPtr;
	
	ID3D10EffectShaderResourceVariable* m_textureArrayPtr;
	ID3D10EffectVectorVariable* lightDirectionPtr;
	ID3D10EffectVectorVariable* diffuseColorPtr;

我们添加了相机位置、高光颜色和高光指数的指针。

	ID3D10EffectVectorVariable* cameraPositionPtr;
	ID3D10EffectVectorVariable* specularColorPtr;
	ID3D10EffectScalarVariable* specularPowerPtr;
};

#endif

Specmapshaderclass.cpp

////////////////////////////////////////////////////////////////////////////////
// Filename: specmapshaderclass.cpp
////////////////////////////////////////////////////////////////////////////////
#include "specmapshaderclass.h"


SpecMapShaderClass::SpecMapShaderClass()
{
	m_effect = 0;
	m_technique = 0;
	m_layout = 0;

	m_worldMatrixPtr = 0;
	m_viewMatrixPtr = 0;
	m_projectionMatrixPtr = 0;
	
	m_textureArrayPtr = 0;
	lightDirectionPtr = 0;
	diffuseColorPtr = 0;

在构造函数中将指针初始化为null。

	cameraPositionPtr = 0;
	specularColorPtr = 0;
	specularPowerPtr = 0;
}


SpecMapShaderClass::SpecMapShaderClass(const SpecMapShaderClass& other)
{
}


SpecMapShaderClass::~SpecMapShaderClass()
{
}


bool SpecMapShaderClass::Initialize(ID3D10Device* device, HWND hwnd)
{
	bool result;

加载新的specmap.fx HLSL shader文件。

	// Initialize the shader that will be used to draw the triangles.
	result = InitializeShader(device, hwnd, L"../Engine/specmap.fx");
	if(!result)
	{
		return false;
	}

	return true;
}


void SpecMapShaderClass::Shutdown()
{
	// Shutdown the shader effect.
	ShutdownShader();

	return;
}

Render方法的参数新添了相机位置、高光颜色和高光指数用于镜面高光的计算。

void SpecMapShaderClass::Render(ID3D10Device* device, int indexCount, D3DXMATRIX worldMatrix, D3DXMATRIX viewMatrix, 
								D3DXMATRIX projectionMatrix, ID3D10ShaderResourceView** textureArray, D3DXVECTOR3 lightDirection, 
								D3DXVECTOR4 diffuseColor, D3DXVECTOR3 cameraPosition, D3DXVECTOR4 specularColor, 
								float specularPower)
{
	// Set the shader parameters that it will use for rendering.
	SetShaderParameters(worldMatrix, viewMatrix, projectionMatrix, textureArray, lightDirection, diffuseColor, cameraPosition, 
						specularColor, specularPower);

	// Now render the prepared buffers with the shader.
	RenderShader(device, indexCount);

	return;
}


bool SpecMapShaderClass::InitializeShader(ID3D10Device* device, HWND hwnd, WCHAR* filename)
{
	HRESULT result;
	ID3D10Blob* errorMessage;
	D3D10_INPUT_ELEMENT_DESC polygonLayout[5];
	unsigned int numElements;
    D3D10_PASS_DESC passDesc;


	// Initialize the error message.
	errorMessage = 0;

	// Load the shader in from the file.
	result = D3DX10CreateEffectFromFile(filename, NULL, NULL, "fx_4_0", D3D10_SHADER_ENABLE_STRICTNESS, 0, 
										device, NULL, NULL, &m_effect, &errorMessage, NULL);
	if(FAILED(result))
	{
		// If the shader failed to compile it should have writen something to the error message.
		if(errorMessage)
		{
			OutputShaderErrorMessage(errorMessage, hwnd, filename);
		}
		// If there was  nothing in the error message then it simply could not find the shader file itself.
		else
		{
			MessageBox(hwnd, filename, L"Missing Shader File", MB_OK);
		}

		return false;
	}

Technique名称修改为SpecMapTechnique。

	// Get a pointer to the technique inside the shader.
	m_technique = m_effect->GetTechniqueByName("SpecMapTechnique");
	if(!m_technique)
	{
		return false;
	}

	// Now setup the layout of the data that goes into the shader.
	// This setup needs to match the VertexType stucture in the ModelClass and in the shader.
	polygonLayout[0].SemanticName = "POSITION";
	polygonLayout[0].SemanticIndex = 0;
	polygonLayout[0].Format = DXGI_FORMAT_R32G32B32_FLOAT;
	polygonLayout[0].InputSlot = 0;
	polygonLayout[0].AlignedByteOffset = 0;
	polygonLayout[0].InputSlotClass = D3D10_INPUT_PER_VERTEX_DATA;
	polygonLayout[0].InstanceDataStepRate = 0;

	polygonLayout[1].SemanticName = "TEXCOORD";
	polygonLayout[1].SemanticIndex = 0;
	polygonLayout[1].Format = DXGI_FORMAT_R32G32_FLOAT;
	polygonLayout[1].InputSlot = 0;
	polygonLayout[1].AlignedByteOffset = D3D10_APPEND_ALIGNED_ELEMENT;
	polygonLayout[1].InputSlotClass = D3D10_INPUT_PER_VERTEX_DATA;
	polygonLayout[1].InstanceDataStepRate = 0;

	polygonLayout[2].SemanticName = "NORMAL";
	polygonLayout[2].SemanticIndex = 0;
	polygonLayout[2].Format = DXGI_FORMAT_R32G32B32_FLOAT;
	polygonLayout[2].InputSlot = 0;
	polygonLayout[2].AlignedByteOffset = D3D10_APPEND_ALIGNED_ELEMENT;
	polygonLayout[2].InputSlotClass = D3D10_INPUT_PER_VERTEX_DATA;
	polygonLayout[2].InstanceDataStepRate = 0;

	polygonLayout[3].SemanticName = "TANGENT";
	polygonLayout[3].SemanticIndex = 0;
	polygonLayout[3].Format = DXGI_FORMAT_R32G32B32_FLOAT;
	polygonLayout[3].InputSlot = 0;
	polygonLayout[3].AlignedByteOffset = D3D10_APPEND_ALIGNED_ELEMENT;
	polygonLayout[3].InputSlotClass = D3D10_INPUT_PER_VERTEX_DATA;
	polygonLayout[3].InstanceDataStepRate = 0;

	polygonLayout[4].SemanticName = "BINORMAL";
	polygonLayout[4].SemanticIndex = 0;
	polygonLayout[4].Format = DXGI_FORMAT_R32G32B32_FLOAT;
	polygonLayout[4].InputSlot = 0;
	polygonLayout[4].AlignedByteOffset = D3D10_APPEND_ALIGNED_ELEMENT;
	polygonLayout[4].InputSlotClass = D3D10_INPUT_PER_VERTEX_DATA;
	polygonLayout[4].InstanceDataStepRate = 0;

	// Get a count of the elements in the layout.
    numElements = sizeof(polygonLayout) / sizeof(polygonLayout[0]);

	// Get the description of the first pass described in the shader technique.
    m_technique->GetPassByIndex(0)->GetDesc(&passDesc);

	// Create the input layout.
    result = device->CreateInputLayout(polygonLayout, numElements, passDesc.pIAInputSignature, passDesc.IAInputSignatureSize, 
									   &m_layout);
	if(FAILED(result))
	{
		return false;
	}

	// Get pointers to the three matrices inside the shader so we can update them from this class.
    m_worldMatrixPtr = m_effect->GetVariableByName("worldMatrix")->AsMatrix();
	m_viewMatrixPtr = m_effect->GetVariableByName("viewMatrix")->AsMatrix();
    m_projectionMatrixPtr = m_effect->GetVariableByName("projectionMatrix")->AsMatrix();

	// Get pointer to the texture array resource inside the shader.
	m_textureArrayPtr = m_effect->GetVariableByName("shaderTextures")->AsShaderResource();

	// Get a pointer to the light direction and color variables inside the shader.
	lightDirectionPtr = m_effect->GetVariableByName("lightDirection")->AsVector();
	diffuseColorPtr = m_effect->GetVariableByName("diffuseColor")->AsVector();

获取指向shader中的相机位置、高光颜色和高光指数的指针。

	// Get pointers to the specular components inside the shader.
	cameraPositionPtr = m_effect->GetVariableByName("cameraPosition")->AsVector();
	specularColorPtr = m_effect->GetVariableByName("specularColor")->AsVector();
	specularPowerPtr = m_effect->GetVariableByName("specularPower")->AsScalar();

	return true;
}


void SpecMapShaderClass::ShutdownShader()
{

在ShutdownShader方法中释放已创建的指针。

	// Release the specular light components.
	cameraPositionPtr = 0;
	specularColorPtr = 0;
	specularPowerPtr = 0;

	// Release the light pointers.
	lightDirectionPtr = 0;
	diffuseColorPtr = 0;

	// Release the pointer to the texture array in the shader file.
	m_textureArrayPtr = 0;

	// Release the pointers to the matrices inside the shader.
	m_worldMatrixPtr = 0;
	m_viewMatrixPtr = 0;
	m_projectionMatrixPtr = 0;

	// Release the pointer to the shader layout.
	if(m_layout)
	{
		m_layout->Release();
		m_layout = 0;
	}

	// Release the pointer to the shader technique.
	m_technique = 0;

	// Release the pointer to the shader.
	if(m_effect)
	{
		m_effect->Release();
		m_effect = 0;
	}

	return;
}


void SpecMapShaderClass::OutputShaderErrorMessage(ID3D10Blob* errorMessage, HWND hwnd, WCHAR* shaderFilename)
{
	char* compileErrors;
	unsigned long bufferSize, i;
	ofstream fout;


	// Get a pointer to the error message text buffer.
	compileErrors = (char*)(errorMessage->GetBufferPointer());

	// Get the length of the message.
	bufferSize = errorMessage->GetBufferSize();

	// Open a file to write the error message to.
	fout.open("shader-error.txt");

	// Write out the error message.
	for(i=0; i<bufferSize; i++)
	{
		fout << compileErrors[i];
	}

	// Close the file.
	fout.close();

	// Release the error message.
	errorMessage->Release();
	errorMessage = 0;

	// Pop a message up on the screen to notify the user to check the text file for compile errors.
	MessageBox(hwnd, L"Error compiling shader.  Check shader-error.txt for message.", shaderFilename, MB_OK);

	return;
}

SetShaderParameters方法的参数新添了相机位置、高光颜色和高光指数。

void SpecMapShaderClass::SetShaderParameters(D3DXMATRIX worldMatrix, D3DXMATRIX viewMatrix, D3DXMATRIX projectionMatrix, 
											 ID3D10ShaderResourceView** textureArray, D3DXVECTOR3 lightDirection, 
											 D3DXVECTOR4 diffuseColor, D3DXVECTOR3 cameraPosition, D3DXVECTOR4 specularColor,
											 float specularPower)
{
	// Set the world matrix variable inside the shader.
    m_worldMatrixPtr->SetMatrix((float*)&worldMatrix);

	// Set the view matrix variable inside the shader.
	m_viewMatrixPtr->SetMatrix((float*)&viewMatrix);

	// Set the projection matrix variable inside the shader.
    m_projectionMatrixPtr->SetMatrix((float*)&projectionMatrix);

	// Bind the texture array.
	m_textureArrayPtr->SetResourceArray(textureArray, 0, 3);

	// Set the direction of the light.
	lightDirectionPtr->SetFloatVector((float*)&lightDirection);

	// Set the diffuse color of the light.
    diffuseColorPtr->SetFloatVector((float*)&diffuseColor);

下面的代码设置相机位置、高光颜色和高光指数。

	// Set the position of the camera.
	cameraPositionPtr->SetFloatVector((float*)&cameraPosition);

	// Set the specular color of the light.
	specularColorPtr->SetFloatVector((float*)&specularColor);

	// Set the specular power of the light.
	specularPowerPtr->SetFloat(specularPower);

	return;
}


void SpecMapShaderClass::RenderShader(ID3D10Device* device, int indexCount)
{
    D3D10_TECHNIQUE_DESC techniqueDesc;
	unsigned int i;
	

	// Set the input layout.
	device->IASetInputLayout(m_layout);

	// Get the description structure of the technique from inside the shader so it can be used for rendering.
    m_technique->GetDesc(&techniqueDesc);

    // Go through each pass in the technique (should be just one currently) and render the triangles.
	for(i=0; i<techniqueDesc.Passes; ++i)
    {
        m_technique->GetPassByIndex(i)->Apply(0);
        device->DrawIndexed(indexCount, 0, 0);
    }

	return;
}

Graphicsclass.h

////////////////////////////////////////////////////////////////////////////////
// Filename: graphicsclass.h
////////////////////////////////////////////////////////////////////////////////
#ifndef _GRAPHICSCLASS_H_
#define _GRAPHICSCLASS_H_


/////////////
// GLOBALS //
/////////////
const bool FULL_SCREEN = true;
const bool VSYNC_ENABLED = true;
const float SCREEN_DEPTH = 1000.0f;
const float SCREEN_NEAR = 0.1f;


///////////////////////
// MY CLASS INCLUDES //
///////////////////////
#include "d3dclass.h"
#include "cameraclass.h"
#include "modelclass.h"

新的SpecMapShaderClass头文件包含在GraphicsClass头中。

#include "specmapshaderclass.h"
#include "lightclass.h"


////////////////////////////////////////////////////////////////////////////////
// Class name: GraphicsClass
////////////////////////////////////////////////////////////////////////////////
class GraphicsClass
{
public:
	GraphicsClass();
	GraphicsClass(const GraphicsClass&);
	~GraphicsClass();

	bool Initialize(int, int, HWND);
	void Shutdown();
	bool Frame();
	bool Render();

private:
	D3DClass* m_D3D;
	CameraClass* m_Camera;
	ModelClass* m_Model;

创建新的SpecMapShaderClass对象。

	SpecMapShaderClass* m_SpecMapShader;
	LightClass* m_Light;
};

#endif

Graphicsclass.cpp

下面的代码只包含与上一个教程不同的部分。

////////////////////////////////////////////////////////////////////////////////
// Filename: graphicsclass.cpp
////////////////////////////////////////////////////////////////////////////////
#include "graphicsclass.h"


GraphicsClass::GraphicsClass()
{
	m_D3D = 0;
	m_Camera = 0;
	m_Model = 0;

在构造函数中将SpecMapShaderClass对象初始化为null。

	m_SpecMapShader = 0;
	m_Light = 0;
}


GraphicsClass::GraphicsClass(const GraphicsClass& other)
{
}


GraphicsClass::~GraphicsClass()
{
}


bool GraphicsClass::Initialize(int screenWidth, int screenHeight, HWND hwnd)
{
	bool result;
	D3DXMATRIX baseViewMatrix;

		
	// Create the Direct3D object.
	m_D3D = new D3DClass;
	if(!m_D3D)
	{
		return false;
	}

	// Initialize the Direct3D object.
	result = m_D3D->Initialize(screenWidth, screenHeight, VSYNC_ENABLED, hwnd, FULL_SCREEN, SCREEN_DEPTH, SCREEN_NEAR);
	if(!result)
	{
		MessageBox(hwnd, L"Could not initialize Direct3D.", L"Error", MB_OK);
		return false;
	}

	// Create the camera object.
	m_Camera = new CameraClass;
	if(!m_Camera)
	{
		return false;
	}

	// Initialize a base view matrix with the camera for 2D user interface rendering.
	m_Camera->SetPosition(0.0f, 0.0f, -1.0f);
	m_Camera->Render();
	m_Camera->GetViewMatrix(baseViewMatrix);

	// Create the model object.
	m_Model = new ModelClass;
	if(!m_Model)
	{
		return false;
	}

模型对象是一个立方体,颜色纹理为stone02.dds,法线贴图为bump02.dds,高光贴图为spec02.dds,这三张纹理会被加载到ModelClass对象中的纹理数组中。

	// Initialize the model object.
	result = m_Model->Initialize(m_D3D->GetDevice(), "../Engine/data/cube.txt", L"../Engine/data/stone02.dds", 
								 L"../Engine/data/bump02.dds", L"../Engine/data/spec02.dds");
	if(!result)
	{
		MessageBox(hwnd, L"Could not initialize the model object.", L"Error", MB_OK);
		return false;
	}

创建并初始化SpecMapShaderClass对象。

	// Create the specular map shader object.
	m_SpecMapShader = new SpecMapShaderClass;
	if(!m_SpecMapShader)
	{
		return false;
	}

	// Initialize the specular map shader object.
	result = m_SpecMapShader->Initialize(m_D3D->GetDevice(), hwnd);
	if(!result)
	{
		MessageBox(hwnd, L"Could not initialize the specular map shader object.", L"Error", MB_OK);
		return false;
	}

	// Create the light object.
	m_Light = new LightClass;
	if(!m_Light)
	{
		return false;
	}

设置光源的属性。

	// Initialize the light object.
	m_Light->SetDiffuseColor(1.0f, 1.0f, 1.0f, 1.0f);
	m_Light->SetDirection(0.0f, 0.0f, 1.0f);
	m_Light->SetSpecularColor(1.0f, 1.0f, 1.0f, 1.0f);
	m_Light->SetSpecularPower(16.0f);

	return true;
}


void GraphicsClass::Shutdown()
{
	// Release the light object.
	if(m_Light)
	{
		delete m_Light;
		m_Light = 0;
	}

在Shutdown方法中释放SpecMapShaderClass对象。

	// Release the specular map shader object.
	if(m_SpecMapShader)
	{
		m_SpecMapShader->Shutdown();
		delete m_SpecMapShader;
		m_SpecMapShader = 0;
	}

	// Release the model object.
	if(m_Model)
	{
		m_Model->Shutdown();
		delete m_Model;
		m_Model = 0;
	}

	// Release the camera object.
	if(m_Camera)
	{
		delete m_Camera;
		m_Camera = 0;
	}

	// Release the Direct3D object.
	if(m_D3D)
	{
		m_D3D->Shutdown();
		delete m_D3D;
		m_D3D = 0;
	}

	return;
}


bool GraphicsClass::Frame()
{
	// Set the position of the camera.
	m_Camera->SetPosition(0.0f, 0.0f, -5.0f);

	return true;
}


bool GraphicsClass::Render()
{
	D3DXMATRIX worldMatrix, viewMatrix, projectionMatrix, orthoMatrix;
	static float rotation = 0.0f;


	// Clear the buffers to begin the scene.
	m_D3D->BeginScene(0.0f, 0.0f, 0.0f, 1.0f);

	// Generate the view matrix based on the camera's position.
	m_Camera->Render();

	// Get the world, view, projection, and ortho matrices from the camera and d3d objects.
	m_D3D->GetWorldMatrix(worldMatrix);
	m_Camera->GetViewMatrix(viewMatrix);
	m_D3D->GetProjectionMatrix(projectionMatrix);
	m_D3D->GetOrthoMatrix(orthoMatrix);

	// Update the rotation variable each frame.
	rotation += (float)D3DX_PI * 0.0025f;
	if(rotation > 360.0f)
	{
		rotation -= 360.0f;
	}

	// Rotate the world matrix by the rotation value.
	D3DXMatrixRotationY(&worldMatrix, rotation);

	// Put the model vertex and index buffers on the graphics pipeline to prepare them for drawing.
	m_Model->Render(m_D3D->GetDevice());

使用specular map shader绘制立方体模型。

	// Render the model using the specular map shader.
	m_SpecMapShader->Render(m_D3D->GetDevice(), m_Model->GetIndexCount(), worldMatrix, viewMatrix, projectionMatrix, 
							m_Model->GetTextureArray(), m_Light->GetDirection(), m_Light->GetDiffuseColor(), 
							m_Camera->GetPosition(), m_Light->GetSpecularColor(), m_Light->GetSpecularPower());

	// Present the rendered scene to the screen.
	m_D3D->EndScene();

	return true;
}

总结

使用高光映射可以让我们控制每个像素的镜面高光强度,创建不同的高光效果。

程序截图

练习

1.编译并运行程序,你会在屏幕上看到如上图所示的旋转立方体,按escape退出程序。

2.创建不同的高光贴图观察效果的不同。

3.修改像素着色器,使程序只显示高光效果而不显示纹理。

4.在GraphicsClass中修改光源对象的强度观察效果的不同。

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发布时间:2012/8/8 下午4:14:54  阅读次数:6347

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