OpenGL, shaders and strange lightning on notebooks - opengl

I have to write a simple OpenGL game. When I'm running it on my PC everything is good. Unfortunately when I run it on laptop it has some problems.
PC:
http://imagizer.imageshack.us/v2/800x600q90/11/i48o.png
Laptop:
http://imagizer.imageshack.us/v2/800x600q90/543/zdpf.png
This is my code for fragment shader:
varying vec3 normal, lightDir[3], eyeVec;
uniform sampler2D myTexture;
const float cos_outer_cone_angle = 0.73;
void main (void)
{
vec4 final_color = (gl_FrontLightModelProduct.sceneColor * gl_FrontMaterial.ambient) + 1.2*((gl_LightSource[0].ambient) * gl_FrontMaterial.ambient);
for(int j=1;j<2;j++){
final_color+=(gl_FrontLightModelProduct.sceneColor * gl_FrontMaterial.ambient) + ((gl_LightSource[j].ambient) * gl_FrontMaterial.ambient);
}
vec3 L[5];
vec3 D[5];
vec3 E = normalize(eyeVec);
vec3 R[5];
float specular[5];
float cos_cur_angle[5];
float cos_inner_cone_angle[5];
float cos_inner_minus_outer_angle[5];
float spot[5];
vec3 N = normalize(normal);
float lambertTerm[5];
for(int i=0;i<3;i++){
L[i]=normalize(lightDir[i]);
D[i]=normalize(gl_LightSource[i].spotDirection);
cos_cur_angle[i]=dot(-L[i], D[i]);
cos_inner_cone_angle[i] = gl_LightSource[i].spotCosCutoff;
cos_inner_minus_outer_angle[i] = cos_inner_cone_angle[i] - cos_outer_cone_angle;
spot[i] = clamp((cos_cur_angle[i] - cos_outer_cone_angle) / cos_inner_minus_outer_angle[i], 0.0,1.0);
lambertTerm[i] = max( dot(N,L[i]), 0.0);
R[i] = reflect(-L[i], N);
specular[i] = pow( max(dot(R[i], E), 0.0), gl_FrontMaterial.shininess );
if(lambertTerm[i] >0.0){
final_color += gl_LightSource[i].diffuse * gl_FrontMaterial.diffuse * lambertTerm[i] *1.5* spot[i];
final_color += gl_LightSource[i].specular * gl_FrontMaterial.specular * specular[i] *3.0* spot[i];
}
}
gl_FragColor = final_color * texture2D(myTexture, vec2(gl_TexCoord[0]));
}
And this is for Vertex Shader:
varying vec3 normal, lightDir[3], eyeVec;
void main()
{
normal = gl_NormalMatrix * gl_Normal;
vec3 vVertex = vec3(gl_ModelViewMatrix * gl_Vertex);
for(int i=0;i<3;i++){
lightDir[i] = vec3(gl_LightSource[i].position.xyz - vVertex);
}
eyeVec = -vVertex;
gl_TexCoord[0] = gl_MultiTexCoord0;
gl_Position = ftransform();
}
PC graphics is Radeon HD6770 and Notebook GPU is Geforce GT325M.
I don't know where is the problem. Is it shaders or terrain loading or what.

Related

Have any guys experienced the same occasion with me about ssao in OpenGL?

Most of the shader codes are follow the instruction of LearnOpenGL. I could make sure that the g-buffer and noise data pass into the shader are correct. It seems like some kind of dislocation, but But I really can't figure out why this happened.
misplace ssao
#version 450 core
out float OUT_FragColor;
in vec2 TexCoords;
uniform sampler2D g_position;
uniform sampler2D g_normal;
uniform sampler2D noise_texture;
struct CameraInfo
{
vec4 position;
mat4 view;
mat4 projection;
};
layout(std140, binding = 0) uniform Camera
{
CameraInfo camera;
};
float radius = 0.5;
float bias = 0.025;
uniform int noise_tex_size;
void main()
{
const vec2 noise_scale = vec2(1280.0/noise_tex_size, 720.0/noise_tex_size);
vec3 frag_pos = texture(g_position, TexCoords).xyz;
vec3 normal = normalize(texture(g_normal, TexCoords).xyz);
vec3 random_vec = normalize(texture(noise_texture, TexCoords * noise_scale).xyz);
vec3 tangent = normalize(random_vec - normal * dot(random_vec, normal));
vec3 bitangent = cross(normal, tangent);
mat3 TBN = mat3(tangent, bitangent, normal);
float occlusion = 0.f;
for(int i = 0; i < sample_array.length(); ++i)
{
vec3 sample_pos = TBN * sample_array[i].xyz;
sample_pos = frag_pos + sample_pos * radius;
vec4 offset = vec4(sample_pos, 1.0);
offset = camera.projection * offset; // from view to clip-space
offset.xyz /= offset.w; // perspective divide ?????
offset.xyz = offset.xyz * 0.5 + 0.5; // transform to range 0.0 - 1.0
float sample_depth = texture(g_position, offset.xy).z;
float range_check = smoothstep(0.f, 1.f, radius / abs(frag_pos.z - sample_depth));
occlusion += (sample_depth >= sample_pos.z + bias ? 1.0 : 0.0) * range_check; //ignore sample points that too near the origin point
}
occlusion = 1.f - (occlusion / sample_array.length());
OUT_FragColor = occlusion;
}
transform the g_postion and g_normal into model space
FragPos = (camera.view * vec4(WorldPos, 1.0)).xyz;
mat4 normal_matrix = camera.view * mat4(transpose(inverse(mat3(model))));
FragNormal = mat3(normal_matrix) * normal;

Volumetric Light not rendering volume correctly

I've been following this tutorial (https://www.programmersought.com/article/68075912719/) to get volumetric light. But I am not getting the correct output.
The shadow volume is incorrectly rendered and I am not sure what I am doing wrong. My vertex and fragment shader looks exactly like the tutorial but still I'm not getting correct output.
Here is the vertex shader code
#version 450 core
layout (location = 0) in vec3 position;
layout (location = 1) in vec2 texCoord;
layout (location = 2) in vec3 normal;
uniform mat4 model;
uniform mat4 vp;
uniform float zFar;
uniform float fov;;
uniform float aspectRatio;
out vec2 TexCoord;
out vec2 farPlanePos;
void main(void){
gl_Position = vec4(position, 1.0);
TexCoord = vec2 (texCoord.x, 1 - texCoord.y);
float t = tan(fov/2);
farPlanePos.x = (TexCoord.x * 2 - 1) * zFar * t * aspectRatio;
farPlanePos.y = (TexCoord.y * 2 - 1) * zFar * t;
}
And Here is the fragment shader code
#version 450 core
in vec2 TexCoord;
uniform vec3 cameraPos;
uniform vec3 lightPos;
uniform vec3 lightColor;
uniform mat4 invViewMatrix;
uniform mat4 invProjectionMatrix;
uniform float ambientStrength;
uniform sampler2D gPosition;
uniform sampler2D gNormal;
uniform sampler2D gAlbedoSpec;
uniform sampler2D gDepth;
uniform sampler2D shadowMapTexture;
in vec2 farPlanePos;
uniform float zFar;
uniform float zNear;
float g = 0.0f;
uniform mat4 lightViewMatrix;
uniform mat4 projectionMatrix;
uniform mat4 viewMatrix;
vec3 yellow_light = vec3(1,198.0/255.0,107.0/255.0);
out vec4 finalColor;
// use linear z depth
vec3 ComputeWorldPos(float depth){
vec4 pos = vec4(vec3(farPlanePos.x, farPlanePos.y, -zFar) * depth , 1.0f);
vec4 ret = invViewMatrix * pos;
return ret.xyz / ret.w;
}
bool IsInShadow(vec4 worldPos){
float fShadow = 0.0;
vec4 lightPos = (lightViewMatrix * (worldPos));
float fDistance = -lightPos.z / zFar;
lightPos = projectionMatrix * lightPos;
vec2 uv = lightPos.xy / lightPos.w * 0.5 + vec2(0.5f, 0.5f);
uv.x = clamp(uv.x, 0.0f, 1.0f);
uv.y = clamp(uv.y, 0.0f, 1.0f);
float offset = 0.5f/zFar;
float distanceMap = texture2D(shadowMapTexture, uv).r;
return fDistance - offset > distanceMap;
}
void main(void){
float depth = texture2D(gDepth, TexCoord).w;
vec3 total_light;
// volume light
{
float I = 0.0f;
float d = depth * zFar;
int virtual_plane_num = 100;
int begin = int(virtual_plane_num * zNear / (d - zNear));
int end = int(virtual_plane_num * (zFar - d) / (d - zNear));
for(int j = begin; j <= virtual_plane_num + begin; j++)
{
float z = 1.0f * j / (begin + virtual_plane_num + end);
vec3 pos = ComputeWorldPos(z);
if(z < depth && !IsInShadow(vec4(pos,1.0f)))
{
//vec3 lightDis = pos - lightPos;
//vec3 viewDis = pos - cameraPos;
//float lightDis2 = lightDis.x * lightDis.x + lightDis.y * lightDis.y + lightDis.z * lightDis.z;
vec3 lightDir = normalize(pos - lightPos);
vec3 viewDir = normalize(pos - cameraPos);
float cosTheta = dot(lightDir,normalize(-lightPos));
float hg = 1.0f/(4.0f*3.14f)* (1.0f - g*g)/ pow(1.0f + g * g - 2.0f * g * dot(lightDir,-viewDir), 1.5f);
if(cosTheta >0.9){
I += clamp(10 * hg / virtual_plane_num, 0.0f, 1.0f);
}
}
}
I = clamp(I , 0.0f,1.0f);
total_light += I * yellow_light;
}
vec3 normal = texture2D(gNormal, TexCoord).xyz * 2 - 1; //result.xyz * 2 - 1;
vec3 worldPos = ComputeWorldPos(depth);
// parallel lights
/*
{
vec3 ViewDir = normalize( cameraPos - worldPos );
vec3 lightDir = normalize(vec3(0.5,1,0.2) );
vec3 halfDir = normalize(lightDir + ViewDir);
float diffuse = 0.3 * clamp(dot(normal, lightDir), 0, 1) ;
vec3 reflectDir = normalize(reflect(-lightDir,normal));
float specular = 0.3 * pow(clamp(dot(reflectDir,halfDir),0,1),50.0);
vec3 color = (diffuse + specular) *vec3(1,1,1);
total_light += color;
}
*/
vec3 color = vec3(texture2D(gAlbedoSpec,TexCoord));
float ambient = 0.1;
finalColor = vec4(total_light + ambient * color,1);
}
So you can see the vertex and fragment shader code is exactly like the blog, but still the output is different.
Unfortunately it doesn't say how to contact the blogger otherwise I would have asked them directly. So the next best option is stockoverflow, so I am asking here.
Ok after 2 days I was able to fix the issue. I think the isInShadow function is incorrect as it always perspective divies by zFar and also doesnt multiply by projection matrix before getting current depth.
So I replaced the code with learnOpengl shadow calculation as below.
bool IsInShadow(vec4 worldPos){
vec4 lightPos = (lightViewMatrix * (worldPos));
//float fDistance = -lightPos.z/ zFar;
lightPos = projectionMatrix * lightPos;
vec3 projCoords = lightPos.xyz / lightPos.w ;
projCoords = projCoords* 0.5 + 0.5f;
//uv.x = clamp(uv.x, 0.0f, 1.0f);
//uv.y = clamp(uv.y, 0.0f, 1.0f);
float offset = 0.5f/zFar;
float distanceMap = texture2D(shadowMapTexture, projCoords.xy).r;
return projCoords.z - offset > distanceMap;
}
And now the code works!!

Screen Space Reflections Artifacts

When I implemented SSR I encountered the problem of artifacts. Below I present the code and screenshots.
Fragment SSR shader:
#version 330 core
uniform sampler2D normalMap; // in view space
uniform sampler2D colorMap;
uniform sampler2D reflectionStrengthMap;
uniform sampler2D positionMap; // in view space
uniform mat4 projection;
uniform vec3 skyColor = vec3(0.1, 0, 0.5);
in vec2 texCoord;
layout (location = 0) out vec4 fragColor;
const int binarySearchCount = 10;
const int rayMarchCount = 30;
const float step = 0.05;
const float LLimiter = 0.2;
const float minRayStep = 0.2;
vec3 getPosition(in vec2 texCoord) {
return texture(positionMap, texCoord).xyz;
}
vec2 binarySearch(inout vec3 dir, inout vec3 hitCoord, inout float dDepth) {
float depth;
vec4 projectedCoord;
for(int i = 0; i < binarySearchCount; i++) {
projectedCoord = projection * vec4(hitCoord, 1.0);
projectedCoord.xy /= projectedCoord.w;
projectedCoord.xy = projectedCoord.xy * 0.5 + 0.5;
depth = getPosition(projectedCoord.xy).z;
dDepth = hitCoord.z - depth;
dir *= 0.5;
if(dDepth > 0.0)
hitCoord += dir;
else
hitCoord -= dir;
}
projectedCoord = projection * vec4(hitCoord, 1.0);
projectedCoord.xy /= projectedCoord.w;
projectedCoord.xy = projectedCoord.xy * 0.5 + 0.5;
return vec2(projectedCoord.xy);
}
vec2 rayCast(vec3 dir, inout vec3 hitCoord, out float dDepth) {
dir *= step;
for (int i = 0; i < rayMarchCount; i++) {
hitCoord += dir;
vec4 projectedCoord = projection * vec4(hitCoord, 1.0);
projectedCoord.xy /= projectedCoord.w;
projectedCoord.xy = projectedCoord.xy * 0.5 + 0.5;
float depth = getPosition(projectedCoord.xy).z;
dDepth = hitCoord.z - depth;
if((dir.z - dDepth) < 1.2 && dDepth <= 0.0) return binarySearch(dir, hitCoord, dDepth);
}
return vec2(-1.0);
}
void main() {
float reflectionStrength = texture(reflectionStrengthMap, texCoord).r;
if (reflectionStrength == 0) {
fragColor = texture(colorMap, texCoord);
return;
}
vec3 normal = texture(normalMap, texCoord).xyz;
vec3 viewPos = getPosition(texCoord);
// Reflection vector
vec3 reflected = normalize(reflect(normalize(viewPos), normalize(normal)));
// Ray cast
vec3 hitPos = viewPos;
float dDepth;
vec2 coords = rayCast(reflected * max(-viewPos.z, minRayStep), hitPos, dDepth);
float L = length(getPosition(coords) - viewPos);
L = clamp(L * LLimiter, 0, 1);
float error = 1 - L;
vec3 color = texture(colorMap, coords.xy).rgb * error;
if (coords.xy != vec2(-1.0)) {
fragColor = mix(texture(colorMap, texCoord), vec4(color, 1.0), reflectionStrength);
return;
}
fragColor = mix(texture(colorMap, texCoord), vec4(skyColor, 1.0), reflectionStrength);
}
Result without blackout (without * error):
Result with blackout:
Note: blue is filled specifically to see artifacts
And one more question, what is the best way to add fresnel without harming scene?

Shader for a spotlight

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;

OpenGL shader: a spotlight and a directional light

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: