Like the title suggests, I am building a particle system in OpenGL using a geometry shader to create billboards from points. Everything seems okay but it looks like all particles share the rotation and color of the first particle. I've checked the inputs of course.
Here are my current vertex and geometry shaders:
Vertex Shader:
#version 330 core
layout(location=0) in vec4 in_position;
layout(location=2) in float in_angle;
layout(location=3) in vec4 in_color;
uniform mat4 P;
uniform mat4 V;
out VertexData
{
vec4 color;
float angle;
} vertex;
void main()
{
vertex.color = in_color;
vertex.angle = in_angle;
gl_Position = in_position;
}
Geometry shader:
#version 330
layout (points) in;
layout (triangle_strip, max_vertices = 4) out;
uniform mat4 V;
uniform mat4 P;
in VertexData
{
vec4 color;
float angle;
} vertex[];
out vec4 fragColor;
out vec2 texcoord;
mat4 rotationMatrix(vec3 axis, float angle)
{
axis = normalize(axis);
float s = sin(angle);
float c = cos(angle);
float oc = 1.0 - c;
return mat4(oc * axis.x * axis.x + c, oc * axis.x * axis.y - axis.z * s, oc * axis.z * axis.x + axis.y * s, 0.0,
oc * axis.x * axis.y + axis.z * s, oc * axis.y * axis.y + c, oc * axis.y * axis.z - axis.x * s, 0.0,
oc * axis.z * axis.x - axis.y * s, oc * axis.y * axis.z + axis.x * s, oc * axis.z * axis.z + c, 0.0,
0.0, 0.0, 0.0, 1.0);
} // http://www.neilmendoza.com/glsl-rotation-about-an-arbitrary-axis/
void main()
{
mat4 R = rotationMatrix( vec3(0,0,1), vertex[0].angle );
vec4 pos = V * vec4( gl_in[0].gl_Position.xyz, 1.0 );
float size = gl_in[0].gl_Position.w;
texcoord = vec2( 0.0, 0.0);
gl_Position = P * ( pos + vec4( texcoord, 0, 0 ) * R * size );
fragColor = vertex[0].color;
EmitVertex();
texcoord = vec2( 1.0, 0.0);
gl_Position = P * ( pos + vec4( texcoord, 0, 0 ) * R * size );
fragColor = vertex[0].color;
EmitVertex();
texcoord = vec2( 0.0, 1.0);
gl_Position = P * ( pos + vec4( texcoord, 0, 0 ) * R * size );
fragColor = vertex[0].color;
EmitVertex();
texcoord = vec2( 1.0, 1.0);
gl_Position = P * ( pos + vec4( texcoord, 0, 0 ) * R * size );
fragColor = vertex[0].color;
EmitVertex();
EndPrimitive();
}
Am I doing something wrong in here?
Ahh I found out what was causing my problem.
I still had two calls to glVertexAttribDivisor(), from when I was still using glDrawArraysInstanced().
Related
I am coding a vertex and a fragment shader trying to distort the surface of some water and then computing blinn-phong lighting on the surface. I am able to successfully compute the deformed matrices with a simple noise function, but how can I find the distorted normals? Since it isn't a linear transformation I am stuck, could anyone help?
Here are the relevant files:
vertex shader:
#version 150
uniform mat4 u_Model;
uniform mat4 u_ModelInvTr;
uniform mat4 u_ViewProj;
uniform vec4 u_Color;
uniform int u_Time;
in vec4 vs_Pos; // The array of vertex positions passed to the shader
in vec4 vs_Nor; // The array of vertex normals passed to the shader
in vec4 vs_Col; // The array of vertex colors passed to the shader.
in vec2 vs_UV; // UV coords for texture to pass thru to fragment shader
in float vs_Anim; // 0.f or 1.f To pass thru to fragment shader
in float vs_T2O;
out vec4 fs_Pos;
out vec4 fs_Nor;
out vec4 fs_LightVec;
out vec4 fs_Col;
out vec2 fs_UVs;
out float fs_Anim;
out float fs_dimVal;
out float fs_T2O;
uniform vec4 u_CamPos;
out vec4 fs_CamPos;
const vec4 lightDir = normalize(vec4(0.0, 1.f, 0.0, 0));
mat4 rotationMatrix(vec3 axis, float angle) {
axis = normalize(axis);
float s = sin(angle);
float c = cos(angle);
float oc = 1.0 - c;
return mat4(oc * axis.x * axis.x + c, oc * axis.x * axis.y - axis.z * s, oc * axis.z * axis.x + axis.y * s, 0.0, oc * axis.x * axis.y + axis.z * s, oc * axis.y * axis.y + c, oc * axis.y * axis.z - axis.x * s, 0.0,oc * axis.z * axis.x - axis.y * s, oc * axis.y * axis.z + axis.x * s, oc * axis.z * axis.z + c, 0.0, 0.0, 0.0, 0.0, 1.0);
}
vec4 rotateLightVec(float deg, vec4 LV) {
mat4 R = rotationMatrix(vec3(0,0,1), deg);
return R * LV;
}
float random1(vec3 p) {
return fract(sin(dot(p, vec3(127.1, 311.7, 191.999)))*43758.5453);
}
vec3 random2( vec3 p ) {
return fract( sin( vec3(dot(p, vec3(127.1, 311.7, 58.24)), dot(p, vec3(269.5, 183.3, 657.3)), dot(p, vec3(420.69, 69.420, 469.20))) ) * 43758.5453);
}
void main()
{
fs_Col = vs_Col;
fs_UVs = vs_UV;
fs_Anim = vs_Anim;
fs_T2O = vs_T2O;
mat3 invTranspose = mat3(u_ModelInvTr);
fs_Nor = vec4(invTranspose * vec3(vs_Nor), 0);
vec4 modelposition = u_Model * vs_Pos;
if (vs_Anim != 0) { // if we want to animate this surface
// check region in texture to decide which animatable type is drawn
bool lava = fs_UVs.x >= 13.f/16.f && fs_UVs.y < 2.f/16.f;
bool water = !lava && fs_UVs.x >= 13.f/16.f && fs_UVs.y <= 4.f/16.f;
if (water) {
// define an oscillating time so that model can transition back and forth
float t = (cos(u_Time * 0.05) + 1)/2; // u_Time increments by 1 every frame. Domain [0,1]
vec3 temp = random2(vec3(modelposition.x, modelposition.y, modelposition.z)); // range [0, 1]
temp = (temp - 0.5)/25; // [0, 1/scalar]
modelposition.x = mix(modelposition.x - temp.x, modelposition.x + temp.x, t);
modelposition.y = mix(modelposition.y - temp.y, modelposition.y + 3*temp.y, t);
modelposition.z = mix(modelposition.z - temp.z, modelposition.z + temp.z, t);
} else if (lava) {
// define an oscillating time so that model can transition back and forth
float t = (cos(u_Time * 0.01) + 1)/2; // u_Time increments by 1 every frame. Domain [0,1]
vec3 temp = random2(vec3(modelposition.x, modelposition.y, modelposition.z)); // range [0, 1]
temp = (temp - 0.5)/25; // [0, 1/scalar]
modelposition.x = mix(modelposition.x - temp.x, modelposition.x + temp.x, t);
modelposition.y = mix(modelposition.y - temp.y, modelposition.y + 3*temp.y, t);
modelposition.z = mix(modelposition.z - temp.z, modelposition.z + temp.z, t);
}
}
fs_dimVal = random1(modelposition.xyz/100.f);
fs_LightVec = rotateLightVec(0.001 * u_Time, lightDir); // Compute the direction in which the light source lies
fs_CamPos = u_CamPos; // uniform handle for the camera position instead of the inverse
fs_Pos = modelposition;
gl_Position = u_ViewProj * modelposition;// gl_Position is a built-in variable of OpenGL which is
// used to render the final positions of the geometry's vertices
}
fragment shader:
#version 330
uniform vec4 u_Color; // The color with which to render this instance of geometry.
uniform sampler2D textureSampler;
uniform int u_Time;
uniform mat4 u_ViewProj;
uniform mat4 u_Model;
in vec4 fs_Pos;
in vec4 fs_Nor;
in vec4 fs_LightVec;
in vec4 fs_Col;
in vec2 fs_UVs;
in float fs_Anim;
in float fs_T2O;
in float fs_dimVal;
out vec4 out_Col;
in vec4 fs_CamPos;
float random1(vec3 p) {
return fract(sin(dot(p,vec3(127.1, 311.7, 191.999)))
*43758.5453);
}
float random1b(vec3 p) {
return fract(sin(dot(p,vec3(169.1, 355.7, 195.999)))
*95751.5453);
}
float mySmoothStep(float a, float b, float t) {
t = smoothstep(0, 1, t);
return mix(a, b, t);
}
float cubicTriMix(vec3 p) {
vec3 pFract = fract(p);
float llb = random1(floor(p) + vec3(0,0,0));
float lrb = random1(floor(p) + vec3(1,0,0));
float ulb = random1(floor(p) + vec3(0,1,0));
float urb = random1(floor(p) + vec3(1,1,0));
float llf = random1(floor(p) + vec3(0,0,1));
float lrf = random1(floor(p) + vec3(1,0,1));
float ulf = random1(floor(p) + vec3(0,1,1));
float urf = random1(floor(p) + vec3(1,1,1));
float mixLoBack = mySmoothStep(llb, lrb, pFract.x);
float mixHiBack = mySmoothStep(ulb, urb, pFract.x);
float mixLoFront = mySmoothStep(llf, lrf, pFract.x);
float mixHiFront = mySmoothStep(ulf, urf, pFract.x);
float mixLo = mySmoothStep(mixLoBack, mixLoFront, pFract.z);
float mixHi = mySmoothStep(mixHiBack, mixHiFront, pFract.z);
return mySmoothStep(mixLo, mixHi, pFract.y);
}
float fbm(vec3 p) {
float amp = 0.5;
float freq = 4.0;
float sum = 0.0;
for(int i = 0; i < 8; i++) {
sum += cubicTriMix(p * freq) * amp;
amp *= 0.5;
freq *= 2.0;
}
return sum;
}
void main()
{
vec4 diffuseColor = texture(textureSampler, fs_UVs);
bool apply_lambert = true;
float specularIntensity = 0;
if (fs_Anim != 0) {
// check region in texture to decide which animatable type is drawn
bool lava = fs_UVs.x >= 13.f/16.f && fs_UVs.y < 2.f/16.f;
bool water = !lava && fs_UVs.x >= 13.f/16.f && fs_UVs.y < 4.f/16.f;
if (lava) {
// slowly gyrate texture and lighten and darken with random dimVal from vert shader
vec2 movingUVs = vec2(fs_UVs.x + fs_Anim * 0.065/16 * sin(0.01*u_Time),
fs_UVs.y - fs_Anim * 0.065/16 * sin(0.01*u_Time + 3.14159/2));
diffuseColor = texture(textureSampler, movingUVs);
vec4 warmerColor = diffuseColor + vec4(0.3, 0.3, 0, 0);
vec4 coolerColor = diffuseColor - vec4(0.1, 0.1, 0, 0);
diffuseColor = mix(warmerColor, coolerColor, 0.5 + fs_dimVal * 0.65*sin(0.02*u_Time));
apply_lambert = false;
} else if (water) {
// blend between 3 different points in texture to create a wavy subtle change over time
vec2 offsetUVs = vec2(fs_UVs.x - 0.5f/16.f, fs_UVs.y - 0.5f/16.f);
diffuseColor = texture(textureSampler, fs_UVs);
vec4 altColor = texture(textureSampler, offsetUVs);
altColor.x += fs_dimVal * pow(altColor.x+.15, 5);
altColor.y += fs_dimVal * pow(altColor.y+.15, 5);
altColor.z += 0.5 * fs_dimVal * pow(altColor.z+.15, 5);
diffuseColor = mix(diffuseColor, altColor, 0.5 + 0.35*sin(0.05*u_Time));
offsetUVs -= 0.25f/16.f;
vec4 newColor = texture(textureSampler, offsetUVs);
diffuseColor = mix(diffuseColor, newColor, 0.5 + 0.5*sin(0.025*u_Time)) + fs_dimVal * vec4(0.025);
diffuseColor.a = 0.7;
// ----------------------------------------------------
// Blinn-Phong Shading
// ----------------------------------------------------
vec4 lightDir = normalize(fs_LightVec - fs_Pos);
vec4 viewDir = normalize(fs_CamPos - fs_Pos);
vec4 halfVec = normalize(lightDir + viewDir);
float shininess = 400.f;
float specularIntensity = max(pow(dot(halfVec, normalize(fs_Nor)), shininess), 0);
}
}
// Calculate the diffuse term for Lambert shading
float diffuseTerm = dot(normalize(fs_Nor), normalize(fs_LightVec));
// Avoid negative lighting values
diffuseTerm = clamp(diffuseTerm, 0, 1);
float ambientTerm = 0.3;
float lightIntensity = diffuseTerm + ambientTerm; //Add a small float value to the color multiplier
//to simulate ambient lighting. This ensures that faces that are not
//lit by our point light are not completely black.
vec3 col = diffuseColor.rgb;
// Compute final shaded color
if (apply_lambert) {
col = col * lightIntensity + col * specularIntensity;
}
// & Check the rare, special case where we draw face between two diff transparent blocks as opaque
if (fs_T2O != 0) {
out_Col = vec4(col, 1.f);
} else {
out_Col = vec4(col, diffuseColor.a);
}
// distance fog!
vec4 fogColor = vec4(0.6, 0.75, 0.9, 1.0);
float FC = gl_FragCoord.z / gl_FragCoord.w / 124.f;
float falloff = clamp(1.05 - exp(-1.05f * (FC - 0.9f)), 0.f, 1.f);
out_Col = mix(out_Col, fogColor, falloff);
}
I tried implementing blinn-phong in the fragment shader, but I think it is wrong simple from the wrong normals. I think this can be done with some sort of tangent and cross product solution, but how can I know the tangent of the surface given we only know the vertex position?
I am not using unity, just bare c++ and most of the answers I am finding online are for java or unity which I do not understand.`
I want to create a similar background with a shader to these images:
:
These are just blurred blobs with colors, distributed across the whole page:
Here's my current progress: https://codesandbox.io/s/lucid-bas-wvlzl9?file=/src/components/Background/Background.tsx
Vertex shader:
varying vec2 vUv;
void main() {
vUv = uv;
gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
}
Fragment shader:
precision highp float;
uniform float uTime;
uniform float uAmplitude;
uniform float uFrequency;
varying vec2 vUv;
uniform vec2 uResolution;
vec4 Sphere(vec2 position, float radius)
{
// float dist = radius / distance(vUv, position);
// float strength = 0.01 / distance(vUv, position);
float strength = 0.1 / distance(vec2(vUv.x, (vUv.y - 0.5) * 8. + 0.5), vec2(0.));
return vec4(strength * strength);
}
void main()
{
vec2 uv = vUv;
vec4 pixel = vec4(0.0, 0.0, 0.0, 0.0);
vec2 positions[4];
positions[0] = vec2(.5, .5);
// positions[1] = vec2(sin(uTime * 3.0) * 0.5, (cos(uTime * 1.3) * 0.6) + vUv.y);
// positions[2] = vec2(sin(uTime * 2.1) * 0.1, (cos(uTime * 1.9) * 0.8) + vUv.y);
// positions[3] = vec2(sin(uTime * 1.1) * 1.1, (cos(uTime * 2.6) * 0.7) + vUv.y);
for (int i = 0; i < 2; i++)
pixel += Sphere(positions[i], 0.22);
pixel = pixel * pixel;
gl_FragColor = pixel;
}
For each blob, you can multiply it's color by a a noise function and then a 2D gaussian curve centered in a random point. Then add all the blobs together. I only added the ones of the adjacent cells to make it scrollable and the numbers in the for loops might be increased for bigger blobs.
here is my code :
#ifdef GL_ES
precision mediump float;
#endif
uniform vec2 u_resolution;
uniform vec2 u_mouse;
uniform float u_time;
const float blobSize = 0.125;
const float cellSize = .75;
const float noiseScale = .375;
const float background = .125;
const float blobsLuminosity = .75;
const float blobsSaturation = .5;
vec2 random2(vec2 st){
st = vec2( dot(st,vec2(127.1,311.7)),
dot(st,vec2(269.5,183.3)) );
return -1.0 + 2.0*fract(sin(st)*43758.5453123);
}
// Gradient Noise by Inigo Quilez - iq/2013
// https://www.shadertoy.com/view/XdXGW8
float noise(vec2 st) {
vec2 i = floor(st);
vec2 f = fract(st);
vec2 u = f*f*(3.0-2.0*f);
return mix( mix( dot( random2(i + vec2(0.0,0.0) ), f - vec2(0.0,0.0) ),
dot( random2(i + vec2(1.0,0.0) ), f - vec2(1.0,0.0) ), u.x),
mix( dot( random2(i + vec2(0.0,1.0) ), f - vec2(0.0,1.0) ),
dot( random2(i + vec2(1.0,1.0) ), f - vec2(1.0,1.0) ), u.x), u.y)*.5+.5;
}
float gaussFunction(vec2 st, vec2 p, float r) {
return exp(-dot(st-p, st-p)/2./r/r);
}
// Function from Iñigo Quiles
// https://www.shadertoy.com/view/MsS3Wc
vec3 hsb2rgb( in vec3 c ){
vec3 rgb = clamp(abs(mod(c.x*6.0+vec3(0.0,4.0,2.0),
6.0)-3.0)-1.0,
0.0,
1.0 );
rgb = rgb*rgb*(3.0-2.0*rgb);
return c.z * mix( vec3(1.0), rgb, c.y);
}
vec3 hash32(vec2 p)
{
vec3 p3 = fract(vec3(p.xyx) * vec3(.1031, .1030, .0973));
p3 += dot(p3, p3.yxz+33.33);
return fract((p3.xxy+p3.yzz)*p3.zyx);
}
vec3 blobs(vec2 st){
vec2 i = floor(st/cellSize);
vec3 c = vec3(0.);
for(int x = -1; x <= 1; x++)
for(int y = -1; y <= 1; y++){
vec3 h = hash32(i+vec2(x, y));
c += hsb2rgb(vec3(h.z, blobsSaturation, blobsLuminosity)) * gaussFunction(st/cellSize, i + vec2(x, y) + h.xy, blobSize) * smoothstep(0., 1., noise(noiseScale*st/cellSize / blobSize));
//c += hsb2rgb(vec3(h.z, blobsSaturation, blobsLuminosity)) * gaussFunction(st/cellSize, i + vec2(x, y) + h.xy, blobSize) * noise(noiseScale*st/cellSize / blobSize);
}
return c + vec3(background);
}
float map(float x, float a, float b, float c, float d){
return (x-a)/(b-a)*(d-c)+c;
}
void main() {
vec2 st = gl_FragCoord.xy/u_resolution.xy;
st.x *= u_resolution.x/u_resolution.y;
vec3 color = vec3(0.0);
color = vec3(blobs(st - u_mouse/u_resolution.xy*4.));
gl_FragColor = vec4(color,1.0);
}
made in this shader editor.
the problem is that i pass few lights to the shader but it showing shadow only for the first one.
the lighting applied also for the lights that their shadows are not seen.
i checked the shadow maps and they being passed correctly.
the fragment shader:
#version 420 compatibility
#define MAX_LIGHTS 8
struct lightSource
{
vec4 position;
vec4 diffuse;
vec4 specular;
float constantAttenuation, linearAttenuation, quadraticAttenuation;
float spotCutoff, spotExponent, intensity;
vec3 spotDirection;
sampler2D TexShadow;
samplerCube TexShadowPoint;
};
struct material
{
vec4 ambient;
vec4 diffuse;
vec4 specular;
float shininess;
};
uniform material frontMaterial;
uniform lightSource lights[MAX_LIGHTS];
uniform int numberOfLights;
uniform vec4 scene_ambient;
uniform mat4 inversedViewMatrix;
uniform sampler2D Tex;
uniform sampler2D TexNorm;
in vec4 position; // position of the vertex (and fragment) in world space
in vec3 varyingNormalDirection; // surface normal vector in world space
in vec2 ex_UV;
in vec4 ShadowCoords[MAX_LIGHTS];
vec2 poissonDisk[16] = vec2[](
vec2( -0.94201624, -0.39906216 ), vec2( 0.94558609, -0.76890725 ),
vec2( -0.094184101, -0.92938870 ), vec2( 0.34495938, 0.29387760 ),
vec2( -0.91588581, 0.45771432 ), vec2( -0.81544232, -0.87912464 ),
vec2( -0.38277543, 0.27676845 ), vec2( 0.97484398, 0.75648379 ),
vec2( 0.44323325, -0.97511554 ), vec2( 0.53742981, -0.47373420 ),
vec2( -0.26496911, -0.41893023 ), vec2( 0.79197514, 0.19090188 ),
vec2( -0.24188840, 0.99706507 ), vec2( -0.81409955, 0.91437590 ),
vec2( 0.19984126, 0.78641367 ), vec2( 0.14383161, -0.14100790 )
);
float rand(vec2 co)
{
return fract(sin(dot(co, vec2(12.9898, 78.233)) * 43758.5453));
}
float linstep(float low, float high, float v)
{
return clamp((v-low)/(high-low), 0.0, 1.0);
}
float VSM(sampler2D depths, vec2 uv, float compare)
{
vec2 moments = texture2D(depths, uv).xy;
float p = smoothstep(compare - 0.02, compare, moments.x);
float variance = max(moments.y - moments.x*moments.x, -0.001);
float d = compare - moments.x;
float p_max;
p_max = linstep(0.6, 1.0, variance / (variance + d*d));
return clamp(max(p, p_max), 0.0, 1.0) / 2;
}
void main(void)
{
vec3 normalDirection;
//sample the normal map and covert from 0:1 range to -1:1 range
if (texture2D(TexNorm, ex_UV).rgb != vec3(0.0, 0.0, 0.0))
{
vec3 mapped_Normals = texture2D(TexNorm, ex_UV).rgb * 2.0 - 1.0;
normalDirection = normalize(mapped_Normals); //normal mapped normals
}
else
normalDirection = normalize(varyingNormalDirection);
vec4 texColor = texture2D(Tex, ex_UV);// usual processing of texture coordinates
vec3 viewDirection = normalize(vec3(inversedViewMatrix * vec4(0.0, 0.0, 0.0, 1.0) - position));
vec3 lightDirection;
float attenuation;
//initialize total lighting with ambient lighting
vec3 totalAmbientDiffuse = vec3(scene_ambient) * vec3(frontMaterial.ambient);
vec3 totalSpecular;
for (int index = 0; index < numberOfLights; index++) // for all light sources
{
float Visibility;
if (lights[index].position.w == 0.0) // directional light
{
attenuation = 1.0; // no attenuation
lightDirection = normalize(vec3(lights[index].position));
//int num = int(rand(position.xyz) * 16);
Visibility = VSM(lights[index].TexShadow, ShadowCoords[index].xy + poissonDisk[int(rand(position.xy + vec2(position.z,-position.z)) * 16)] /2000, ShadowCoords[index].z);
}
else // point light or spotlight (or other kind of light)
{
vec3 positionToLightSource = vec3(lights[index].position - position);
float Distance = length(positionToLightSource);
lightDirection = normalize(positionToLightSource);
attenuation = 1.0 / (lights[index].constantAttenuation + lights[index].linearAttenuation * Distance + lights[index].quadraticAttenuation * Distance * Distance);
if (lights[index].spotCutoff <= 90.0) // spotlight
{
Visibility = VSM(lights[index].TexShadow, ShadowCoords[index].xy / ShadowCoords[index].w + poissonDisk[int(rand(position.xy + vec2(position.z,-position.z)) * 16)] / 700, ShadowCoords[index].z / ShadowCoords[index].w);
float clampedCosine = max(0.0, dot(-lightDirection, normalize(lights[index].spotDirection)));
if (clampedCosine < cos(radians(lights[index].spotCutoff))) // outside of spotlight cone
{
attenuation = 0.0;
}
else
{
attenuation = attenuation * pow(clampedCosine, lights[index].spotExponent);
}
}
else // point light
{
//point light shadow calculations
}
}
vec3 diffuseReflection = attenuation * vec3(lights[index].diffuse) * vec3(frontMaterial.diffuse) * max(0.0, dot(normalDirection, lightDirection));
vec3 specularReflection;
if (dot(normalDirection, lightDirection) < 0.0) // light source on the wrong side
{
specularReflection = vec3(0.0, 0.0, 0.0); // no specular reflection
}
else // light source on the right side
{
specularReflection = attenuation * vec3(lights[index].specular) * vec3(frontMaterial.specular)
* pow(max(0.0, dot(reflect(-lightDirection, normalDirection), viewDirection)), frontMaterial.shininess);
}
totalAmbientDiffuse += diffuseReflection * lights[index].intensity * Visibility;
totalSpecular += specularReflection * lights[index].intensity * Visibility;
}
gl_FragColor = vec4(totalAmbientDiffuse, 1.0) * texColor + vec4(totalSpecular, 1.0);
}
How can I get this shader to have a smooth edge on the spot light instead of a hard one? In addition, the shader has to cope with a variable value of GL_SPOT_CUTOFF. Note that not all the lights are spot lights -- GL_LIGHT0 is a point light.
varying vec3 N;
varying vec3 v;
#define MAX_LIGHTS 2
void main (void)
{
vec4 finalColour;
float spotEffect;
for (int i=0; i<MAX_LIGHTS; i++)
{
vec3 L = normalize(gl_LightSource[i].position.xyz - v);
vec3 E = normalize(-v);
vec3 R = normalize(-reflect(L,N));
spotEffect = dot(normalize(gl_LightSource[i].spotDirection),
normalize(-L));
if (spotEffect > gl_LightSource[i].spotCosCutoff) {
vec4 Iamb = gl_FrontLightProduct[i].ambient;
vec4 Idiff = gl_FrontLightProduct[i].diffuse * max(dot(N,L), 0.0);
Idiff = clamp(Idiff, 0.0, 1.0);
vec4 Ispec = gl_FrontLightProduct[i].specular
* pow(max(dot(R,E),0.0),0.3*gl_FrontMaterial.shininess);
Ispec = clamp(Ispec, 0.0, 1.0);
finalColour += Iamb + Idiff + Ispec;
}
}
gl_FragColor = gl_FrontLightModelProduct.sceneColor + finalColour;
}
The scene looks like this:
This shader from http://www.ozone3d.net/tutorials/glsl_lighting_phong_p3.php produces the soft edges to the spotlight you are after.
[Pixel_Shader]
varying vec3 normal, lightDir, eyeVec;
const float cos_outer_cone_angle = 0.8; // 36 degrees
void main (void)
{
vec4 final_color =
(gl_FrontLightModelProduct.sceneColor * gl_FrontMaterial.ambient) +
(gl_LightSource[0].ambient * gl_FrontMaterial.ambient);
vec3 L = normalize(lightDir);
vec3 D = normalize(gl_LightSource[0].spotDirection);
float cos_cur_angle = dot(-L, D);
float cos_inner_cone_angle = gl_LightSource[0].spotCosCutoff;
float cos_inner_minus_outer_angle =
cos_inner_cone_angle - cos_outer_cone_angle;
//****************************************************
// Don't need dynamic branching at all, precompute
// falloff(i will call it spot)
float spot = 0.0;
spot = clamp((cos_cur_angle - cos_outer_cone_angle) /
cos_inner_minus_outer_angle, 0.0, 1.0);
//****************************************************
vec3 N = normalize(normal);
float lambertTerm = max( dot(N,L), 0.0);
if(lambertTerm > 0.0)
{
final_color += gl_LightSource[0].diffuse *
gl_FrontMaterial.diffuse *
lambertTerm * spot;
vec3 E = normalize(eyeVec);
vec3 R = reflect(-L, N);
float specular = pow( max(dot(R, E), 0.0),
gl_FrontMaterial.shininess );
final_color += gl_LightSource[0].specular *
gl_FrontMaterial.specular *
specular * spot;
}
gl_FragColor = final_color;
I want to have two light sources: a directional one and a spotlight. I cannot seem to get what I am doing wrong -- probably not understanding how shaders work! I get the first light fine but no sign of the effects of the second one (aka spotlight). Here is the fragement shader that I came up with:
varying vec4 diffuse,ambientGlobal, ambient;
varying vec3 normal,lightDir,halfVector;
varying float dist;
void main()
{
vec3 n, halfV, viewV, ldir;
float NdotL, NdotHV;
vec4 color = ambientGlobal;
float att, spotEffect;
n = normalize(normal);
NdotL = max(dot(n,normalize(lightDir)),0.0);
if (NdotL > 0.0) {
att = 1.0 / (gl_LightSource[0].constantAttenuation +
gl_LightSource[0].linearAttenuation * dist +
gl_LightSource[0].quadraticAttenuation * dist * dist);
color += att * (diffuse * NdotL + ambient);
halfV = normalize(halfVector);
NdotHV = max(dot(n,halfV),0.0);
color += att * gl_FrontMaterial.specular * gl_LightSource[0].specular * pow(NdotHV,gl_FrontMaterial.shininess);
spotEffect = dot(normalize(gl_LightSource[1].spotDirection), normalize(-lightDir));
if (spotEffect > gl_LightSource[1].spotCosCutoff) {
spotEffect = pow(spotEffect, gl_LightSource[1].spotExponent);
att = spotEffect / (gl_LightSource[1].constantAttenuation +
gl_LightSource[1].linearAttenuation * dist +
gl_LightSource[1].quadraticAttenuation * dist * dist);
color += att * (diffuse * NdotL + ambient);
halfV = normalize(halfVector);
NdotHV = max(dot(n,halfV),0.0);
color += att * gl_FrontMaterial.specular * gl_LightSource[1].specular * pow(NdotHV,gl_FrontMaterial.shininess);
}
}
gl_FragColor = color;
}
PS: Surely this is a problem that has been solved.... Anyone?
Here is what I came up with:
The vertex shader:
varying vec3 N;
varying vec3 v;
void main(void)
{
v = vec3(gl_ModelViewMatrix * gl_Vertex);
N = normalize(gl_NormalMatrix * gl_Normal);
gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
}
And the fragment shader:
varying vec3 N;
varying vec3 v;
#define MAX_LIGHTS 2
void main (void)
{
vec4 finalColour;
for (int i=0; i<MAX_LIGHTS; i++)
{
vec3 L = normalize(gl_LightSource[i].position.xyz - v);
vec3 E = normalize(-v);
vec3 R = normalize(-reflect(L,N));
vec4 Iamb = gl_FrontLightProduct[i].ambient;
vec4 Idiff = gl_FrontLightProduct[i].diffuse * max(dot(N,L), 0.0);
Idiff = clamp(Idiff, 0.0, 1.0);
vec4 Ispec = gl_FrontLightProduct[i].specular
* pow(max(dot(R,E),0.0),0.3*gl_FrontMaterial.shininess);
Ispec = clamp(Ispec, 0.0, 1.0);
finalColour += Iamb + Idiff + Ispec;
}
gl_FragColor = gl_FrontLightModelProduct.sceneColor + finalColour;
}
Which give this image: