The Shader compiles successfully, but the program crashes as soon as rendering starts... This is the error i get: "no uniform with name 'u_texture' in shader". This is what my shader looks like:
#ifdef GL_ES
precision mediump float;
#endif
uniform float time;
uniform vec2 mouse;
uniform vec2 resolution;
varying vec2 surfacePosition;
#define MAX_ITER 10
void main( void ) {
vec2 p = surfacePosition*4.0;
vec2 i = p;
float c = 0.0;
float inten = 1.0;
for (int n = 0; n < MAX_ITER; n++) {
float t = time * (1.0 - (1.0 / float(n+1)));
i = p + vec2(
cos(t - i.x) + sin(t + i.y),
sin(t - i.y) + cos(t + i.x)
);
c += 1.0/length(vec2(
p.x / (sin(i.x+t)/inten),
p.y / (cos(i.y+t)/inten)
)
);
}
c /= float(MAX_ITER);
gl_FragColor = vec4(vec3(pow(c,1.5))*vec3(0.99, 0.97, 1.8), 1.0);
}
Can someone please help me. I don't know what I'm doing wrong. BTW, this is shader i found on the internet, so I know it is working, the only problem is making it work with libgdx.
libGDX's SpriteBatch assumes that your shader will have u_texture uniform. To overcome just add
ShaderProgram.pedantic = false;(Javadoc) before putting your shader program into the SpriteBatch.
UPDATE: raveesh is right about shader compiler vanishing unused uniforms and attributes, but libGDX wraps OpenGL shader in custom ShaderProgram.
Not only should you add the uniform u_texture in your shader program, you should also use it, otherwise it will be optimized away by the shader compiler.
But looking at you shader, you don't seem to need the uniform anyway, so check your program for something like shader.setUniformi("u_texture", 0); and remove the line. It should work fine then.
Related
I am trying to implement a Streak shader, which is described here:
http://www.chrisoat.com/papers/Oat-SteerableStreakFilter.pdf
Short explanation: Samples a point with a 1d kernel in a given direction. The kernel size grows exponentially in each step. Color values are weighted based on distance to sampled point and summed. The result is a smooth tail/smear/light streak effect on that direction. Here is the frag shader:
precision highp float;
uniform sampler2D u_texture;
varying vec2 v_texCoord;
uniform float u_Pass;
const float kernelSize = 4.0;
const float atten = 0.95;
vec4 streak(in float pass, in vec2 texCoord, in vec2 dir, in vec2 pixelStep) {
float kernelStep = pow(kernelSize, pass - 1.0);
vec4 color = vec4(0.0);
for(int i = 0; i < 4; i++) {
float sampleNum = float(i);
float weight = pow(atten, kernelStep * sampleNum);
vec2 sampleTexCoord = texCoord + ((sampleNum * kernelStep) * (dir * pixelStep));
vec4 texColor = texture2D(u_texture, sampleTexCoord) * weight;
color += texColor;
}
return color;
}
void main() {
vec2 iResolution = vec2(512.0, 512.0);
vec2 pixelStep = vec2(1.0, 1.0) / iResolution.xy;
vec2 dir = vec2(1.0, 0.0);
float pass = u_Pass;
vec4 streakColor = streak(pass, v_texCoord, dir, pixelStep);
gl_FragColor = vec4(streakColor.rgb, 1.0);
}
It was going to be used for a starfield type of effect. And here is the implementation on ShaderToy which works fine:
https://www.shadertoy.com/view/ll2BRG
(Note: Disregard the first shader in Buffer A, it just filters out the dim colors in the input texture to emulate a star field since afaik ShaderToy doesn't allow uploading custom textures)
But when I use the same shader in my own code and render using ping-pong FrameBuffers, it looks different. Here is my own implementation ported over to WebGL:
https://jsfiddle.net/1b68eLdr/87755/
I basically create 2 512x512 buffers, ping-pong the shader 4 times increasing kernel size at each iteration according to the algorithm and render the final iteration on the screen.
The problem is visible banding, and my streaks/tails seem to be losing brightness a lot faster: (Note: the image is somewhat inaccurate, the lengths of the streaks are same/correct, its color values that are wrong)
I have been struggling with this for a while in Desktop OpenGl / LWJGL, I ported it over to WebGL/Javascript and uploaded on JSFiddle in hopes someone can spot what the problem is. I suspect it's either about texture coordinates or FrameBuffer configuration since shaders are exactly the same.
The reason it works on Shadertoys is because it uses a floating-point render target.
Simply use gl.FLOAT as the type of your framebuffer texture and the issue is fixed (I could verify it with the said modification on your JSFiddle).
So do this in your createBackingTexture():
// Just request the extension (MUST be done).
gl.getExtension('OES_texture_float');
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, this._width, this._height, 0, gl.RGBA, gl.FLOAT, null);
I'm trying to implement a shader for grass in cocos2d-x. The shader works OK on texture loaded with Sprite::create() and it looks like this:
http://i.stack.imgur.com/Rv4rd.png
The problem is that if I'm using Sprite::createWithSpriteFrameName() and applying the same shader it looks like the offsets are wrong when calculating height also because it is moving at a larger degree, like it is using the height of the full texture from plist file:
http://i.stack.imgur.com/of6Ku.png
Here is the shader code:
VSH
attribute vec4 a_position;
attribute vec2 a_texCoord;
attribute vec4 a_color;
#ifdef GL_ES
varying lowp vec4 v_fragmentColor;
varying mediump vec2 v_texCoord;
#else
varying vec4 v_fragmentColor;
varying vec2 v_texCoord;
#endif
void main()
{
gl_Position = CC_PMatrix * a_position;
v_fragmentColor = a_color;
v_texCoord = a_texCoord;
}
FSH
#ifdef GL_ES
precision mediump float;
#endif
varying vec2 v_texCoord;
uniform float speed;
uniform float bendFactor;
void main()
{
float height = 1.0 - v_texCoord.y;
float offset = pow(height, 2.5);
offset *= (sin(CC_Time[1] * speed) * bendFactor);
gl_FragColor = texture2D(CC_Texture0, fract(vec2(v_texCoord.x + offset, v_texCoord.y))).rgba;
}
If what is happening is not clear I can provide some videos. Thank you.
EDIT
Here is the code used to generate the grass sprite:
// Smaller grass
auto grass2 = Sprite::createWithSpriteFrameName("grass2.png");
grass2->setAnchorPoint(Vec2(0.5f, 0));
grass2->setPosition(Vec2(230, footer1->getContentSize().height * 0.25f));
// Apply "grass" shader
grass2->setGLProgramState(mat->getTechniqueByName("grass")->getPassByIndex(0)->getGLProgramState()->clone());
grass2->getGLProgramState()->setUniformFloat("speed", RandomHelper::random_real(0.5f, 3.0f));
grass2->getGLProgramState()->setUniformFloat("bendFactor", RandomHelper::random_real(0.1f, 0.2f));
It's hard to tell what's happening without seeing more of your code...
If I should guess I would say that the problem is related to trimming in TexturePacker.
If you set TrimMode=Trim the sprite is stripped from transparency. This makes the sprite smaller. Cocos2d-x also only renders the smaller portion of the sprite, compensating the difference between the original sprite and the trimmed sprite with an offset vector.
I propose that you either try not to trim the sprite or try polygon trimming.
The problem was with TexturePacker trimming but also with offsets in v_texCoord.
The solution was to calculate offsets in cocos2d-x and pass them to shader.
I calculated offsets using following code:
Rect grass2Offset(
grass2->getTextureRect().origin.x / grass2->getTexture()->getContentSize().width,
grass2->getTextureRect().origin.y / grass2->getTexture()->getContentSize().height,
grass2->getTextureRect().size.width / grass2->getTexture()->getContentSize().width,
grass2->getTextureRect().size.height / grass2->getTexture()->getContentSize().height
);
Next I pass the height offset and scale to shader as uniforms using:
grass2->getGLProgramState()->setUniformFloat("heightOffset", grass2Offset.origin.y);
grass2->getGLProgramState()->setUniformFloat("heightScale", 1 / grass2Offset.size.height);
Last, the shader is using the offset like this:
#ifdef GL_ES
precision mediump float;
#endif
varying vec2 v_texCoord;
uniform float speed;
uniform float bendFactor;
uniform float heightOffset;
uniform float heightScale;
void main()
{
float height = 1.0 - (v_texCoord.y - heightOffset) * heightScale;
float offset = pow(height, 2.5);
offset *= (sin(CC_Time[1] * speed) * bendFactor);
gl_FragColor = texture2D(CC_Texture0, fract(vec2(v_texCoord.x + offset, v_texCoord.y))).rgba;
}
currently I am working on a OSG Project for my study and wrote a CelShading shader (alongside a simpleFog Shader). I first render with the CelShader along with the depth buffer to Texture and then use the fogShader. Everything works fine on my AMD Radeon HD 7950 and on my Intel HD4400 (although it is slow on the last), both running Windows. However, on a Quadro 600 runnning Linux, the Shader compiles without error, but is still wrong, the light is dulled and because of the lack of some light spots, it seems that not every light in the Scene is used. The whole toon effect is also gone.
I confirmed the Shader working on another AMD, a ATI Mobility HD3400.
But on other NVIDIAs, like a GTX 670 or 660 TI oder 560 TI (this time windows) the Shader is not working. First it was totally messed up because of non-uniform flow, but after I fixed it it is still not working.
I have this Problem now for some days and it is giving me a headache. I do not know what am I missing, why is it working on a simple Intel HD 4400 but not on high end NVIDIA Cards?
Strangely, the fogShader is working perfectly on every system and gives me the nice fog I want.
Does anyone have an idea? The Uniforms are set for the toonTex, but texture0 is not set, because the model is uv-mapped with blender, but the textures seem to work just fine (look at the Pony in the Screens). I assuming 0 is used as layout for texture0, which is perfectly valid,as far as I know. Here is a Video showing the shader on a GTX 660 TI. Something seems to work, if there is only one light, but it is not how it should look like, on a Radeon HD 7950 it is like this (ignore the black border, screenshot issue).
The light is cleary different.
EDIT: Just did another test: on the Intel HD 4400 and Windows, it is working. But the same System running Linux is showing only a whole lot of White with some outlines but no textures at all.
Anyone any suggestion?
The sources for the shaders are here:
celShader.vert
#version 120
varying vec3 normalModelView;
varying vec4 vertexModelView;
uniform bool zAnimation;
uniform float osg_FrameTime;
void main()
{
normalModelView = gl_NormalMatrix * gl_Normal;
vertexModelView = gl_ModelViewMatrix * gl_Vertex;
gl_TexCoord[0] = gl_MultiTexCoord0;
vec4 vertexPos = gl_Vertex;
if(zAnimation){//
vertexPos.z = sin(5.0*vertexPos.z + osg_FrameTime)*0.25;//+ vertexPos.z;
}
gl_Position = gl_ModelViewProjectionMatrix * vertexPos;
}
celShader.frag
#version 120
#define NUM_LIGHTS 5
uniform sampler2D texture0;
uniform sampler2D toonTex;
uniform float osg_FrameTime;
uniform bool tex;
varying vec3 normalModelView;
varying vec4 vertexModelView;
vec4 calculateLightFromLightSource(int lightIndex, bool front){
vec3 lightDir;
vec3 eye = normalize(-vertexModelView.xyz);
vec4 curLightPos = gl_LightSource[lightIndex].position;
//curLightPos.z = sin(10*osg_FrameTime)*4+curLightPos.z;
lightDir = normalize(curLightPos.xyz - vertexModelView.xyz);
float dist = distance( gl_LightSource[lightIndex].position, vertexModelView );
float attenuation = 1.0 / (gl_LightSource[lightIndex].constantAttenuation
+ gl_LightSource[lightIndex].linearAttenuation * dist
+ gl_LightSource[lightIndex].quadraticAttenuation * dist * dist);
float z = length(vertexModelView);
vec4 color;
vec3 n = normalize(normalModelView);
vec3 nBack = normalize(-normalModelView);
float intensity = dot(n,lightDir); //NdotL, Lambert
float intensityBack = dot(nBack,lightDir); //NdotL, Lambert
//-Phong Modell
vec3 reflected = normalize(reflect( -lightDir, n));
float specular = pow(max(dot(reflected, eye), 0.0), gl_FrontMaterial.shininess);
vec3 reflectedBack = normalize(reflect( -lightDir, nBack));
float specularBack = pow(max(dot(reflectedBack, eye), 0.0), gl_BackMaterial.shininess);
//Toon-Shading
//2D Toon http://www.cs.rpi.edu/~cutler/classes/advancedgraphics/S12/final_projects/hutchins_kim.pdf
vec4 toonColor = texture2D(toonTex,vec2(intensity,specular));
vec4 toonColorBack = texture2D(toonTex,vec2(intensityBack,specularBack));
if(front){
color += gl_FrontMaterial.ambient * gl_LightSource[lightIndex].ambient[lightIndex];
if(intensity > 0.0){
color += gl_FrontMaterial.diffuse * gl_LightSource[lightIndex].diffuse * intensity * attenuation ;
color += gl_FrontMaterial.specular * gl_LightSource[lightIndex].specular * specular *attenuation ;
}
return color * toonColor;
} else {//back
color += gl_BackMaterial.ambient * gl_LightSource[lightIndex].ambient[lightIndex];
if(intensity > 0.0){
color += gl_BackMaterial.diffuse * gl_LightSource[lightIndex].diffuse * intensityBack * attenuation ;
color += gl_BackMaterial.specular * gl_LightSource[lightIndex].specular * specularBack *attenuation ;
}
return color * toonColorBack;
}
}
void main(void) {
vec4 color = vec4(0.0);
bool front = true;
//non-uniform-flow error correction
//see more here: http://www.opengl.org/wiki/GLSL_Sampler#Non-uniform_flow_control
//and here: http://gamedev.stackexchange.com/questions/32543/glsl-if-else-statement-unexpected-behaviour
vec4 texColor = texture2D(texture0,gl_TexCoord[0].xy);
if(!gl_FrontFacing)
front = false;
for(int i = 0; i< NUM_LIGHTS; i++){
color += calculateLightFromLightSource(i,front);
}
if(tex)
gl_FragColor =color * texColor;
else
gl_FragColor = color;
}
fogShader.vert
#version 120
varying vec4 vertexModelView;
void main()
{
gl_Position = ftransform();
vertexModelView = gl_ModelViewMatrix * gl_Vertex;
gl_TexCoord[0] = gl_MultiTexCoord0;
}
fogShader.frag
varying vec4 vertexModelView;
uniform sampler2D texture0;
uniform sampler2D deepth;
uniform vec3 fogColor;
uniform float zNear;
uniform float zFar;
float linearDepth(float z){
return (2.0 * (zNear+zFar)) / ((zFar + zNear) - z * (zFar - zNear));// -1.0;
}
void main(void){
//Literature
//http://www.ozone3d.net/tutorials/glsl_fog/p04.php and depth_of_field example OSG Cookbook
vec2 deepthPoint = gl_TexCoord[0].xy;
float z = texture2D(deepth, deepthPoint).x;
//fogFactor = (end - z) / (end - start)
z = linearDepth(z);
float fogFactor = (4000*4-z) / (4000*4 - 30*4);
fogFactor = clamp(fogFactor, 0.0, 1.0);
vec4 texColor = texture2D(texture0,gl_TexCoord[0].xy);
gl_FragColor = mix(vec4(fogColor,1.0), texColor,fogFactor);
}
ProgramLinking
osg::ref_ptr<osg::Shader> toonFrag = osgDB::readShaderFile("../Shader/celShader.frag");
osg::ref_ptr<osg::Shader> toonVert = osgDB::readShaderFile("../Shader/" + _vertSource);
osg::ref_ptr<osg::Program> celShadingProgram = new osg::Program;
celShadingProgram->addShader(toonFrag);
celShadingProgram->addShader(toonVert);
osg::ref_ptr<osg::Texture2D> toonTex = new osg::Texture2D;
toonTex->setImage(osgDB::readImageFile("../BlenderFiles/Texturen/toons/" + _toonTex));
toonTex->setFilter(osg::Texture::MIN_FILTER, osg::Texture::NEAREST);
toonTex->setFilter(osg::Texture::MAG_FILTER, osg::Texture::NEAREST);
osg::ref_ptr<osg::StateSet> ss = new osg::StateSet;
ss->setTextureAttributeAndModes(1, toonTex, osg::StateAttribute::OVERRIDE | osg::StateAttribute::ON);
ss->addUniform(new osg::Uniform("toonTex", 1));
ss->setAttributeAndModes(celShadingProgram, osg::StateAttribute::OVERRIDE | osg::StateAttribute::ON);
//TODO NEEED?
ss->setTextureMode(1, GL_TEXTURE_1D, osg::StateAttribute::OVERRIDE | osg::StateAttribute::OFF);
ss->addUniform(new osg::Uniform("tex", true));
ss->addUniform(new osg::Uniform("zAnimation", false));
Okay, I finally found the error.
There was a faulty Line since version zero of my Shader which I overlooked for a whole week (and I am suprised my AMD Driver did not gave my an error, it was just plain wrong!
EDIT: not wrong at all, see comment below!).
This two lines were broken:
color += gl_FrontMaterial.ambient * gl_LightSource[lightIndex].ambient[lightIndex];
color += gl_BackMaterial.ambient * gl_LightSource[lightIndex].ambient[lightIndex];
ambient is of course not an array....
I want to fade the screen to a specific color using glsl
So far this is my glsl code and it works quite well:
uniform sampler2D textureSampler;
uniform vec2 texcoordOffset;
uniform vec3 sp;
uniform vec3 goal;
varying vec4 vertColor;
varying vec4 vertTexcoord;
void main(void) {
vec3 col=texture2D(textureSampler, vertTexcoord.st).rgb;
gl_FragColor = vec4(col+((goal-col)/sp), 1.0);
//gl_FragColor = vec4(col+((goal-col)*sp), 1.0); //as suggested below also this doesn't solve the problem
}
The only problem I have is that with higher sp values the colors aren't faded completly to the new color. I think the problem is caused by the accuracy which with the shader works.
Doas anyone has an Idea how to increase the accuracy?
EDIT:
Could it be that this effect is Driver dependent? I'm using an ATI with the latest drivers maybe someone could try the code on an NVIDIA card?
Let's break it down:
float A, B:
float Mix;
float C = A + (B-A) / Mix;
Now it's fairly easy to see that Mix has to be infinite to create pure A, so it isn't GLSL fault at all. The normally used equation is as follows
float C = A + (B-A) * Mix;
// Let's feed some data:
// Mix = 0 -> C = A;
// Mix = 1 -> C = A + (B - A) = A + B - A = B;
// Mix = 0.5 -> C = A + 0.5*(B - A) = A + 0.5*B - 0.5*A = 0.5*A + 0.5*B
Correct, right?
Change your code to:
gl_FragColor = vec4(col+((goal-col) * sp), 1.0);
And use the range of <0,1> in sp instead. Also, shouldn't sp be actually float? If all of it's components are equal (IOW sp.x == sp.y == sp.z), you can just change it's type and it will work, as referenced here.
Is it possible to somehow modify this fragment shader so that it doesn't use the oes_texture_float extension? Because I get an error on the machine which is supposed to run a webgl animation.
I set up my scene using three.js webglrenderer and a cube with a shadermaterial applied to it. On My macbook pro, everything works fine, but on some windows machine I get the error "float textures not supported" (I've searched and found that this probably has to do with oes_texture_float extension)
So I'm guessing I need to change my fragment shader? Or am I missing the point completely?
<script type="x-shader/x-vertex" id="vertexshader">
// switch on high precision floats
#ifdef GL_ES
precision highp float;
#endif
void main() {
gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
}
</script>
<script type="x-shader/x-fragment" id="fragmentshader">
#ifdef GL_ES
precision mediump float;
#endif
#define PI 3.14159265
uniform float time;
uniform vec2 resolution;
float f(float x) {
return (sin(x * 1.50 * PI ) + 19.0);
}
float q(vec2 p) {
float s = (f(p.x + 0.85)) / 2.0;
float c = smoothstep(0.9, 1.20, 1.0 - abs(p.y - s));
return c;
}
vec3 aurora(vec2 p, float time) {
vec3 c1 = q( vec2(p.x, p.y / 0.051) + vec2(time / 3.0, -0.3)) * vec3(2.90, 0.50, 0.10);
vec3 c2 = q( vec2(p.x, p.y / 0.051) + vec2(time, -0.2)) * vec3(1.3, .6, 0.3);
vec3 c3 = q( vec2(p.x, p.y / 0.051) + vec2(time / 5.0, -0.5)) * vec3(1.7, 0.4, 0.20);
return c1+c2+c3;
}
void main( void ) {
vec2 p = ( gl_FragCoord.xy / resolution.xy );
vec3 c = aurora(p, time);
gl_FragColor = vec4(1.0-c, c);
}
</script>
EDIT: this has nothing to do with the floating point texture, but rather with something in my fragment shader. Three.js gives me the error: "Can't initialise shader, VALIDATE_STATUS"
"Or am I missing the point completely?" - Indeed you are. The shaders don't care about the underlying texture format (you don't even use any textures in those shaders you posted!), so they don't have anything to do with your problem.
It's the application code that uses a float texture somewhere and needs to be changed accordingly. But from the fact that your shader doesn't use any textures at all (and I guess you haven't explicitly created a float texture elsewhere), it's probably three.js' internals that need a float texture somewhere, maybe as render target. So you need to search for ways to disable this requirement if possible.
Unless it's a three.js ism you haven't defined projectionMatrix, modelViewMatrix, and position in your vertex shader.
Try adding
uniform mat4 projectionMatrix;
uniform mat4 modelViewMatrix;
attribute vec4 position;
To the top of the first shader?