使用Triangle_Strips和heightmaps我创建了一个多山的地形，并使用3D平面投影进行纹理处理。对于3D平面投影，我遵循以下链接的第1.5节。 https://developer.nvidia.com/gpugems/GPUGems3/gpugems3_ch01.html
这就是Phong Lighting之前的样子。 Unity纹理，没关系。
这就是它照顾Phong Lighting的方式。请注意，我假设了方向光，所以我假设光方向面向-y轴方向。我把它设为shader.setVec3("light.direction", 0.0f, -0.1f, 0.0f);
地形的某些部分突然变得更亮，就好像光线只在那些部分变强了。
我检查了法线向量是否正确。所以我通过几何着色器将它们可视化。这是结果。
如您所见，法向量实际上是正确的。所以在我的着色器程序中一定有问题。这是代码。首先是顶点着色器。
#version 330 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec3 aNormal;
uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
float scale = 0.5;
out vec2 TexX;
out vec2 TexY;
out vec2 TexZ;
out vec3 blend_weights;
out vec3 FragPos;
out vec3 wNormal;
void main()
{
FragPos = vec3(model * vec4(aPos, 1.0));
blend_weights = abs(aNormal.xyz);
blend_weights = (blend_weights - 0.2) * 0.7;
blend_weights = max(blend_weights, 0);
blend_weights /= (blend_weights.x + blend_weights.y + blend_weights.z);
TexX = aPos.yz * scale;
TexY = aPos.zx * scale;
TexZ = aPos.xy * scale;
wNormal = mat3(transpose(inverse(model))) * aNormal;
gl_Position = projection * view * vec4(FragPos, 1.0);
}
这是我的片段着色器。
#version 330 core
out vec4 FragColor;
struct Material{
//aka terrainTexture;
sampler2D diffuse;
sampler2D specular;
float shininess;
};
struct Light {
// Direction has to be in world coordinates.
vec3 direction;
vec3 ambient;
vec3 diffuse;
vec3 specular;
};
uniform Light light;
uniform Material material;
uniform vec3 viewPos;
in vec3 FragPos; //world Coordinate!
in vec2 TexX;
in vec2 TexY;
in vec2 TexZ;
in vec3 wNormal;
in vec3 blend_weights;
void main()
{
vec4 ColorNoLighting = texture(material.diffuse, TexX)*blend_weights.x + texture(material.diffuse, TexY)*blend_weights.y + texture(material.diffuse, TexZ)*blend_weights.z;
vec3 ambient = light.ambient * ColorNoLighting.xyz;
vec3 norm = normalize(wNormal);
vec3 lightDir = normalize(-light.direction);
float diff = max(dot(norm, lightDir), 0.0);
vec3 diffuse = light.diffuse * diff * ColorNoLighting.xyz;
vec3 viewDir = normalize(viewPos - FragPos);
vec3 reflectDir = reflect(-lightDir, norm);
float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
vec3 specular = light.specular * spec * ColorNoLighting.xyz;
vec3 result = ambient + diffuse + specular;
FragColor = vec4(result, 1.0);
}
最后，这就是我设置所有制服的方式。
shader.use();
shader.setInt("material.diffuse", 0);
shader.setInt("material.specular", 1);
shader.setVec3("light.direction", 0.0f, -0.1f, 0.0f);
shader.setVec3("viewPos", camera.Position);
shader.setVec3("light.ambient", 0.2f, 0.2f, 0.2f);
shader.setVec3("light.diffuse", 0.5f, 0.5f, 0.5f);
shader.setVec3("light.specular", 1.0f, 1.0f, 1.0f);
shader.setFloat("material.shininess", 32.0f);
shader.setMat4("model", model);
shader.setMat4("view", view);
shader.setMat4("projection", projection);
我不明白为什么我的地形的某些部分突然变得如此明亮。任何帮助，将不胜感激。提前致谢！
与Phong镜面高光相比，光的Lambertian漫反射成分较弱。
在着色器代码中，漫反射组件的强度由参数light.diffuse设置：
float diff = max(dot(norm, lightDir), 0.0);
vec3 diffuse = light.diffuse * diff * ColorNoLighting.xyz;
镜面反射分量的强度及其大小由light.specular分别设定material.shininess：
float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
vec3 specular = light.specular * spec * ColorNoLighting.xyz;
注意，如果光泽度参数减小，则镜面高光的大小会增加，但会变得更平滑。
更改参数以解决您的问题。
EG
shader.setVec3("light.diffuse", 1.0f, 1.0f, 1.0f);
shader.setVec3("light.specular", 0.5f, 0.5f, 0.5f);
shader.setFloat("material.shininess", 10.0f);
请参阅示例，该示例演示了参数的效果：
(function loadscene() {
var sliderScale = 100.0
var gl;
var canvas;
var vp_size;
var progDraw;
var bufTorus = {};
function render(deltaMS){
var ambient = document.getElementById( "ambient" ).value / sliderScale;
var diffuse = document.getElementById( "diffuse" ).value / sliderScale;
var specular = document.getElementById( "specular" ).value / sliderScale;
var shininess = Math.max(1, document.getElementById( "shininess" ).value / 2);
document.getElementById( "ambient_val" ).innerHTML = ambient;
document.getElementById( "diffuse_val" ).innerHTML = diffuse;
document.getElementById( "specular_val" ).innerHTML = specular;
document.getElementById( "shininess_val" ).innerHTML = shininess;
Camera.create();
Camera.vp = [canvas.width, canvas.height];
gl.viewport( 0, 0, canvas.width, canvas.height );
gl.enable( gl.DEPTH_TEST );
gl.clearColor( 0.0, 0.0, 0.0, 1.0 );
gl.clear( gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT );
// set up draw shader
ShaderProgram.Use( progDraw );
ShaderProgram.SetUniformMat44( progDraw, "u_projectionMat44", Camera.Perspective() );
ShaderProgram.SetUniformMat44( progDraw, "u_viewMat44", Camera.LookAt() );
ShaderProgram.SetUniform3f( progDraw, "u_lightDir", [-1.0, -0.5, -2.0] )
ShaderProgram.SetUniformFloat( progDraw, "u_ambient", ambient )
ShaderProgram.SetUniformFloat( progDraw, "u_diffuse", diffuse )
ShaderProgram.SetUniformFloat( progDraw, "u_specular", specular )
ShaderProgram.SetUniformFloat( progDraw, "u_shininess", shininess )
var modelMat = IdentityMat44()
modelMat = RotateAxis( modelMat, CalcAng( deltaMS, 13.0 ), 0 );
modelMat = RotateAxis( modelMat, CalcAng( deltaMS, 17.0 ), 1 );
ShaderProgram.SetUniformMat44( progDraw, "u_modelMat44", modelMat );
// draw scene
VertexBuffer.Draw( bufTorus );
requestAnimationFrame(render);
}
function initScene() {
document.getElementById( "ambient" ).value = 0.2 * sliderScale;
document.getElementById( "diffuse" ).value = 0.75 * sliderScale;
document.getElementById( "specular" ).value = 0.75 * sliderScale;
document.getElementById( "shininess" ).value = 20.0;
canvas = document.getElementById( "phong-canvas");
vp_size = [canvas.width, canvas.height];
gl = canvas.getContext( "experimental-webgl" );
if ( !gl )
return;
progDraw = ShaderProgram.Create(
[ { source : "draw-shader-vs", stage : gl.VERTEX_SHADER },
{ source : "draw-shader-fs", stage : gl.FRAGMENT_SHADER }
],
[ "u_projectionMat44", "u_viewMat44", "u_modelMat44",
"u_lightDir", "u_ambient", "u_diffuse", "u_specular", "u_shininess", ] );
progDraw.inPos = gl.getAttribLocation( progDraw, "inPos" );
progDraw.inNV = gl.getAttribLocation( progDraw, "inNV" );
progDraw.inCol = gl.getAttribLocation( progDraw, "inCol" );
if ( progDraw == 0 )
return;
// create torus
var circum_size = 32, tube_size = 32;
var rad_circum = 1.0;
var rad_tube = 0.5;
var torus_pts = [];
var torus_nv = [];
var torus_col = [];
var torus_inx = [];
var col = [1, 0.5, 0.0];
for ( var i_c = 0; i_c < circum_size; ++ i_c ) {
var center = [
Math.cos(2 * Math.PI * i_c / circum_size),
Math.sin(2 * Math.PI * i_c / circum_size) ]
for ( var i_t = 0; i_t < tube_size; ++ i_t ) {
var tubeX = Math.cos(2 * Math.PI * i_t / tube_size)
var tubeY = Math.sin(2 * Math.PI * i_t / tube_size)
var pt = [
center[0] * ( rad_circum + tubeX * rad_tube ),
center[1] * ( rad_circum + tubeX * rad_tube ),
tubeY * rad_tube ]
var nv = [ pt[0] - center[0] * rad_tube, pt[1] - center[1] * rad_tube, tubeY * rad_tube ]
torus_pts.push( pt[0], pt[1], pt[2] );
torus_nv.push( nv[0], nv[1], nv[2] );
torus_col.push( col[0], col[1], col[2] );
var i_cn = (i_c+1) % circum_size
var i_tn = (i_t+1) % tube_size
var i_c0 = i_c * tube_size;
var i_c1 = i_cn * tube_size;
torus_inx.push( i_c0+i_t, i_c0+i_tn, i_c1+i_t, i_c0+i_tn, i_c1+i_t, i_c1+i_tn )
}
}
bufTorus = VertexBuffer.Create(
[ { data : torus_pts, attrSize : 3, attrLoc : progDraw.inPos },
{ data : torus_nv, attrSize : 3, attrLoc : progDraw.inNV },
{ data : torus_col, attrSize : 3, attrLoc : progDraw.inCol } ],
torus_inx
);
window.onresize = resize;
resize();
requestAnimationFrame(render);
}
function resize() {
//vp_size = [gl.drawingBufferWidth, gl.drawingBufferHeight];
vp_size = [window.innerWidth, window.innerHeight]
canvas.width = vp_size[0];
canvas.height = vp_size[1];
}
function Fract( val ) {
return val - Math.trunc( val );
}
function CalcAng( deltaMS, intervall ) {
return Fract( deltaMS / (1000*intervall) ) * 2.0 * Math.PI;
}
function CalcMove( deltaMS, intervall, range ) {
var pos = self.Fract( deltaMS / (1000*intervall) ) * 2.0
var pos = pos < 1.0 ? pos : (2.0-pos)
return range[0] + (range[1] - range[0]) * pos;
}
function EllipticalPosition( a, b, angRag ) {
var a_b = a * a - b * b
var ea = (a_b <= 0) ? 0 : Math.sqrt( a_b );
var eb = (a_b >= 0) ? 0 : Math.sqrt( -a_b );
return [ a * Math.sin( angRag ) - ea, b * Math.cos( angRag ) - eb, 0 ];
}
function IdentityMat44() { return [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1]; }
function RotateAxis(matA, angRad, axis) {
var aMap = [ [1, 2], [2, 0], [0, 1] ];
var a0 = aMap[axis][0], a1 = aMap[axis][1];
var sinAng = Math.sin(angRad), cosAng = Math.cos(angRad);
var matB = matA.slice(0);
for ( var i = 0; i < 16; ++ i ) matB[i] = matA[i];
for ( var i = 0; i < 3; ++ i ) {
matB[a0*4+i] = matA[a0*4+i] * cosAng + matA[a1*4+i] * sinAng;
matB[a1*4+i] = matA[a0*4+i] * -sinAng + matA[a1*4+i] * cosAng;
}
return matB;
}
function Cross( a, b ) { return [ a[1] * b[2] - a[2] * b[1], a[2] * b[0] - a[0] * b[2], a[0] * b[1] - a[1] * b[0], 0.0 ]; }
function Dot( a, b ) { return a[0]*b[0] + a[1]*b[1] + a[2]*b[2]; }
function Normalize( v ) {
var len = Math.sqrt( v[0] * v[0] + v[1] * v[1] + v[2] * v[2] );
return [ v[0] / len, v[1] / len, v[2] / len ];
}
var Camera = {};
Camera.create = function() {
this.pos = [0, 3, 0.0];
this.target = [0, 0, 0];
this.up = [0, 0, 1];
this.fov_y = 90;
this.vp = [800, 600];
this.near = 0.5;
this.far = 100.0;
}
Camera.Perspective = function() {
var fn = this.far + this.near;
var f_n = this.far - this.near;
var r = this.vp[0] / this.vp[1];
var t = 1 / Math.tan( Math.PI * this.fov_y / 360 );
var m = IdentityMat44();
m[0] = t/r; m[1] = 0; m[2] = 0; m[3] = 0;
m[4] = 0; m[5] = t; m[6] = 0; m[7] = 0;
m[8] = 0; m[9] = 0; m[10] = -fn / f_n; m[11] = -1;
m[12] = 0; m[13] = 0; m[14] = -2 * this.far * this.near / f_n; m[15] = 0;
return m;
}
Camera.LookAt = function() {
var mz = Normalize( [ this.pos[0]-this.target[0], this.pos[1]-this.target[1], this.pos[2]-this.target[2] ] );
var mx = Normalize( Cross( this.up, mz ) );
var my = Normalize( Cross( mz, mx ) );
var tx = Dot( mx, this.pos );
var ty = Dot( my, this.pos );
var tz = Dot( [-mz[0], -mz[1], -mz[2]], this.pos );
var m = IdentityMat44();
m[0] = mx[0]; m[1] = my[0]; m[2] = mz[0]; m[3] = 0;
m[4] = mx[1]; m[5] = my[1]; m[6] = mz[1]; m[7] = 0;
m[8] = mx[2]; m[9] = my[2]; m[10] = mz[2]; m[11] = 0;
m[12] = tx; m[13] = ty; m[14] = tz; m[15] = 1;
return m;
}
// shader program object
var ShaderProgram = {};
ShaderProgram.Create = function( shaderList, uniformNames ) {
var shaderObjs = [];
for ( var i_sh = 0; i_sh < shaderList.length; ++ i_sh ) {
var shderObj = this.CompileShader( shaderList[i_sh].source, shaderList[i_sh].stage );
if ( shderObj == 0 )
return 0;
shaderObjs.push( shderObj );
}
var progObj = this.LinkProgram( shaderObjs )
if ( progObj != 0 ) {
progObj.unifomLocation = {};
for ( var i_n = 0; i_n < uniformNames.length; ++ i_n ) {
var name = uniformNames[i_n];
progObj.unifomLocation[name] = gl.getUniformLocation( progObj, name );
}
}
return progObj;
}
ShaderProgram.Use = function( progObj ) { gl.useProgram( progObj ); }
ShaderProgram.SetUniformInt = function( progObj, name, val ) { gl.uniform1i( progObj.unifomLocation[name], val ); }
ShaderProgram.SetUniformFloat = function( progObj, name, val ) { gl.uniform1f( progObj.unifomLocation[name], val ); }
ShaderProgram.SetUniform2f = function( progObj, name, arr ) { gl.uniform2fv( progObj.unifomLocation[name], arr ); }
ShaderProgram.SetUniform3f = function( progObj, name, arr ) { gl.uniform3fv( progObj.unifomLocation[name], arr ); }
ShaderProgram.SetUniformMat44 = function( progObj, name, mat ) { gl.uniformMatrix4fv( progObj.unifomLocation[name], false, mat ); }
ShaderProgram.CompileShader = function( source, shaderStage ) {
var shaderScript = document.getElementById(source);
if (shaderScript) {
source = "";
var node = shaderScript.firstChild;
while (node) {
if (node.nodeType == 3) source += node.textContent;
node = node.nextSibling;
}
}
var shaderObj = gl.createShader( shaderStage );
gl.shaderSource( shaderObj, source );
gl.compileShader( shaderObj );
var status = gl.getShaderParameter( shaderObj, gl.COMPILE_STATUS );
if ( !status ) alert(gl.getShaderInfoLog(shaderObj));
return status ? shaderObj : 0;
}
ShaderProgram.LinkProgram = function( shaderObjs ) {
var prog = gl.createProgram();
for ( var i_sh = 0; i_sh < shaderObjs.length; ++ i_sh )
gl.attachShader( prog, shaderObjs[i_sh] );
gl.linkProgram( prog );
status = gl.getProgramParameter( prog, gl.LINK_STATUS );
if ( !status ) alert("Could not initialise shaders");
gl.useProgram( null );
return status ? prog : 0;
}
var VertexBuffer = {};
VertexBuffer.Create = function( attributes, indices ) {
var buffer = {};
buffer.buf = [];
buffer.attr = []
for ( var i = 0; i < attributes.length; ++ i ) {
buffer.buf.push( gl.createBuffer() );
buffer.attr.push( { size : attributes[i].attrSize, loc : attributes[i].attrLoc } );
gl.bindBuffer( gl.ARRAY_BUFFER, buffer.buf[i] );
gl.bufferData( gl.ARRAY_BUFFER, new Float32Array( attributes[i].data ), gl.STATIC_DRAW );
}
buffer.inx = gl.createBuffer();
gl.bindBuffer( gl.ELEMENT_ARRAY_BUFFER, buffer.inx );
gl.bufferData( gl.ELEMENT_ARRAY_BUFFER, new Uint16Array( indices ), gl.STATIC_DRAW );
buffer.inxLen = indices.length;
gl.bindBuffer( gl.ARRAY_BUFFER, null );
gl.bindBuffer( gl.ELEMENT_ARRAY_BUFFER, null );
return buffer;
}
VertexBuffer.Draw = function( bufObj ) {
for ( var i = 0; i < bufObj.buf.length; ++ i ) {
gl.bindBuffer( gl.ARRAY_BUFFER, bufObj.buf[i] );
gl.vertexAttribPointer( bufObj.attr[i].loc, bufObj.attr[i].size, gl.FLOAT, false, 0, 0 );
gl.enableVertexAttribArray( bufObj.attr[i].loc );
}
gl.bindBuffer( gl.ELEMENT_ARRAY_BUFFER, bufObj.inx );
gl.drawElements( gl.TRIANGLES, bufObj.inxLen, gl.UNSIGNED_SHORT, 0 );
for ( var i = 0; i < bufObj.buf.length; ++ i )
gl.disableVertexAttribArray( bufObj.attr[i].loc );
gl.bindBuffer( gl.ARRAY_BUFFER, null );
gl.bindBuffer( gl.ELEMENT_ARRAY_BUFFER, null );
}
initScene();
})();html,body { margin: 0; overflow: hidden; }
#gui { position : absolute; top : 0; left : 0; }<script id="draw-shader-vs" type="x-shader/x-vertex">
precision mediump float;
attribute vec3 inPos;
attribute vec3 inNV;
attribute vec3 inCol;
varying vec3 vertPos;
varying vec3 vertNV;
varying vec3 vertCol;
uniform mat4 u_projectionMat44;
uniform mat4 u_viewMat44;
uniform mat4 u_modelMat44;
void main()
{
vec3 modelNV = mat3( u_modelMat44 ) * normalize( inNV );
vertNV = mat3( u_viewMat44 ) * modelNV;
vertCol = inCol;
vec4 modelPos = u_modelMat44 * vec4( inPos, 1.0 );
vec4 viewPos = u_viewMat44 * modelPos;
vertPos = viewPos.xyz / viewPos.w;
gl_Position = u_projectionMat44 * viewPos;
}
</script>
<script id="draw-shader-fs" type="x-shader/x-fragment">
precision mediump float;
varying vec3 vertPos;
varying vec3 vertNV;
varying vec3 vertCol;
uniform vec3 u_lightDir;
uniform float u_ambient;
uniform float u_diffuse;
uniform float u_specular;
uniform float u_shininess;
void main()
{
vec3 color = vertCol;
vec3 lightCol = u_ambient * color;
vec3 normalV = normalize( vertNV );
vec3 lightV = normalize( -u_lightDir );
vec3 eyeV = normalize( -vertPos );
// Lambertian
float NdotL = max( 0.0, dot( normalV, lightV ) );
lightCol += NdotL * u_diffuse * color;
// Phong
vec3 reflectV = reflect(-lightV, normalV);
float VdotR = max( 0.0, dot( eyeV, reflectV ) );
float kSpecular = ( u_shininess + 2.0 ) * pow( VdotR, u_shininess ) / ( 2.0 * 3.14159265 );
lightCol += kSpecular * u_specular * color;
gl_FragColor = vec4( lightCol.rgb, 1.0 );
}
</script>
<form id="gui" name="inputs">
<table>
<tr> <td> <font color=#40f040>ambient</font> </td>
<td> <input type="range" id="ambient" min="0" max="100" value="0"/></td> <td> <font color= #CCF><span id="ambient_val">0</span></font> </td> </tr>
<tr> <td> <font color=#40f040>diffuse</font> </td>
<td> <input type="range" id="diffuse" min="0" max="100" value="0"/></td> <td> <font color= #CCF><span id="diffuse_val">0</span></font> </td></tr>
<tr> <td> <font color=#40f040>specular</font> </td>
<td> <input type="range" id="specular" min="0" max="100" value="0"/></td> <td> <font color= #CCF><span id="specular_val">0</span></font> </td></tr>
<tr> <td> <font color=#40f040>shininess</font> </td>
<td> <input type="range" id="shininess" min="0" max="100" value="0"/></td> <td> <font color= #CCF><span id="shininess_val">0</span></font> </td></tr>
</table>
</form>
<canvas id="phong-canvas" style="border: none;"></canvas>