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Java Game APIs & Engines / OpenGL Development / Re: Lighting + Shadow Mapping GLSL

on: 2012-10-04 13:23:31

I have found this tutorial. It is written in Delphi, so I have to change the code a little.
But apparently I did something wrong. GL30.glCheckFramebufferStatus(GL30.GL_FRAMEBUFFER) returns 36054 (GL30.GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT) and if I bind the FBO I get the error "Invalid framebuffer operation".

original code:

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GLuint shadow_map = 0; 
GLuint shadow_fbo = 0;
GLuint shadow_size = 4096;
 
glGenTextures(1, &shadow_map);
glBindTexture(GL_TEXTURE_2D, shadow_map);
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT16, shadow_size, shadow_size, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 
glGenFramebuffersEXT(1, &shadow_fbo);
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, shadow_fbo);
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_TEXTURE_2D, shadow_map, 0);
glDrawBuffer(GL_FALSE);
glReadBuffer(GL_FALSE);
GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);

my code:

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int shadow_map = 0; 
int shadow_fbo = 0;
int shadow_size = 4096;

shadow_map = GL11.glGenTextures();
GL11.glBindTexture(GL11.GL_TEXTURE_2D, shadow_map);
GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, GL14.GL_DEPTH_COMPONENT16, shadow_size, shadow_size, 0, GL11.GL_DEPTH_COMPONENT, GL11.GL_UNSIGNED_BYTE, (ByteBuffer) null);
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_NEAREST);
      
shadow_fbo = GL30.glGenFramebuffers();
GL30.glBindFramebuffer(GL30.GL_FRAMEBUFFER, shadow_fbo);
GL30.glFramebufferTexture2D(GL30.GL_FRAMEBUFFER, GL30.GL_DEPTH_ATTACHMENT, GL11.GL_TEXTURE_2D, shadow_map, 0);
GL11.glDrawBuffer(GL11.GL_FALSE);
GL11.glReadBuffer(GL11.GL_FALSE);
int status = GL30.glCheckFramebufferStatus(GL30.GL_FRAMEBUFFER);

I thought that the problem is in line 7. So I tried to pass an empty ByteBuffer, but that did not work.

2	Java Game APIs & Engines / OpenGL Development / Re: Lighting GLSL	on: 2012-09-27 10:39:10
I have solved the problem. Previously I first rotated and translated the modelviewmatrix and then set the light. Now I rotate the modelviewmatrix first, then set the light and move the modelviewmatrix at the end. But now I would like to use shadow mapping, but I can't find a tutorial, that I understand. I understand the theory (Render the scene from the view of the light, read the z-Buffer and test in the fragment shader, if z is bigger than the z from the rendering from light position), but not how to do this.

Java Game APIs & Engines / OpenGL Development / Lighting + Shadow Mapping GLSL

on: 2012-09-25 20:14:03

Hi, I want to use diffuse and ambient light. My problem is, that if I move with the camera (translate the ModelViewMatrix) the brightness of the faces changes although the light should be fixed.

Here is my vertex shader:

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attribute vec3 position;
attribute vec3 normal;

void main() {
   gl_Position = gl_ModelViewProjectionMatrix * vec4(position, 1);
   gl_Normal = normalize(gl_NormalMatrix * normal);
                     
   vec3 light = normalize(vec3(gl_LightSource[0].position));

   float NdotL = max(dot(gl_Normal, light), 0.0);
                     
   vec4 ambient = gl_FrontMaterial.ambient * gl_LightSource[0].ambient;
   vec4 globalAmbient = gl_LightModel.ambient * gl_FrontMaterial.ambient;
                     
   gl_FrontColor = NdotL * gl_LightSource[0].diffuse + globalAmbient + ambient;
}

I set the light position each frame after translate the MoselViewMatrix:

1	GL11.glLight(GL11.GL_LIGHT0, GL11.GL_POSITION, mPosition);

What should I do?

PS: Is there an IDE/addon for Eclipse for GLSL?

Java Game APIs & Engines / OpenGL Development / Re: glDrawArrays - problem with normals

on: 2012-09-21 12:09:48

Ok, I have read some article about shader.

Now I want to make a vertex shader that simple set the attribute 0 as position of the vertex and the attribute 1 as normal. And a fragment shader that do the same that it does normal (because I have read that I can not use only a vertex shader without fragment shader).

I have found that code in a tutorial. But there are some things I don't understand.

1. Does that mean, that I must set the matrices projModelViewMatrix and normalMatrix each time before I render?
2. How does OpenGL know, that VertexOut.normal is the normal for that vertex? / How I can change the normal in the vertex shader if gl_Normal is readable only?
3. How I can make a "default" fragment shader?
4. Does it makes a difference in performance if I use old GLSL Methodes like ftransform()?
5. Will it be later more complicated to use shadow mapping, if I use me own shader?

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#version 150

layout (std140) uniform Matrices {
   mat4 projModelViewMatrix;
   mat3 normalMatrix;
};

in vec3 position;
in vec3 normal;

out VertexData {
   vec3 normal;
} VertexOut;

void main() {
   VertexOut.normal = normalize(normalMatrix * normal);
   gl_Position = projModelViewMatrix * vec4(position, 1.0);
}

5	Java Game APIs & Engines / OpenGL Development / Re: glDrawArrays - problem with normals	on: 2012-09-20 16:56:29
I've found out that glVertexPointer(...) assumes no GL_BYTE as data type. Maybe it would be better if I do it in a different way, because otherwise I will have to send twice as many bytes for the coordinates to the graphics card. It is important for me that the frame rate is not going down even if I render many cubes and some of them change each frame.

Java Game APIs & Engines / OpenGL Development / Re: glDrawArrays - problem with normals

on: 2012-09-20 10:44:26

I used this command because I was trying to work with this tutorial to make my code ready for future versions of OpenGL (http://lwjgl.org/wiki/index.php?title=The_Quad_with_DrawArrays).

Do you mean so? With this code I get the error: Invalid enum

Here I'd use no VAO. Is this right? And is this a good way to render my cubes? Or are there better?

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ByteBuffer verticesBuffer = BufferUtils.createByteBuffer(numberOfVerices * 6);
verticesBuffer.put(verticesAndNormals, 0, numberOfVerices * 6);
verticesBuffer.flip();
      
vboId = GL15.glGenBuffers();
GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vboId);
GL15.glBufferData(GL15.GL_ARRAY_BUFFER, verticesBuffer, GL15.GL_DYNAMIC_DRAW);
      
GL11.glVertexPointer(3, GL11.GL_BYTE, 6, 0);
GL11.glNormalPointer(GL11.GL_BYTE, 6, 3);

GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);

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GL11.glEnableClientState(GL11.GL_VERTEX_ARRAY);
GL11.glEnableClientState(GL11.GL_NORMAL_ARRAY);

GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vboId);

GL11.glDrawArrays(GL11.GL_QUADS, 0, vertexCount);

GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);

GL11.glDisableClientState(GL11.GL_NORMAL_ARRAY);
GL11.glDisableClientState(GL11.GL_VERTEX_ARRAY);

Java Game APIs & Engines / OpenGL Development / Re: glDrawArrays - problem with normals

on: 2012-09-20 08:40:34

I have tried the following vertex shader.

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#version 150 core

in vec3 in_Position;
in vec3 in_Normal;

void main(){
   gl_Position = in_Position;
   gl_Normal = in_Normal;
}

But it just brought me the following error message: Invalid operation

8	Java Game APIs & Engines / OpenGL Development / Re: glDrawArrays - problem with normals	on: 2012-09-19 19:34:39
I don't use a shader at the moment.

9	Java Game APIs & Engines / OpenGL Development / Re: glDrawArrays - problem with normals	on: 2012-09-19 19:04:23
Quote from: StumpyStrust on 2012-09-19 18:47:02 Make sure your offsets are right as it looks like you are interleaving your VBO. 1 float is 4 bytes. So a 3 float vertex is 4*3 bytes I am still learning this stuff too. Yes I interleaving the VBO and I am sure that it is not because of that. (3 bytes for coordinate, 3 bytes for normals) Could it be that I have to use shaders to tell OpenGL that the second attribute are the normals?

Java Game APIs & Engines / OpenGL Development / glDrawArrays - problem with normals

on: 2012-09-19 18:13:22

Hi, i try to make a Voxel Engine.

I have a VAO that have a VBO. In this are the vertex and the normals of the Cubes.

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vaoId = GL30.glGenVertexArrays();
GL30.glBindVertexArray(vaoId);

ByteBuffer verticesBuffer = BufferUtils.createByteBuffer(numberOfVerices * 6);
verticesBuffer.put(verticesAndNormals, 0, numberOfVerices);
verticesBuffer.flip();

vboId = GL15.glGenBuffers();
GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vboId);
GL15.glBufferData(GL15.GL_ARRAY_BUFFER, verticesBuffer, GL15.GL_DYNAMIC_DRAW);
      
GL20.glVertexAttribPointer(0, 3, GL11.GL_BYTE, false, 6, 0); // vertex
GL20.glVertexAttribPointer(1, 3, GL11.GL_BYTE, false, 6, 3); // normals

GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
GL30.glBindVertexArray(0);

I can render the cubes like this:

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GL30.glBindVertexArray(vaoId);
GL20.glEnableVertexAttribArray(0);

GL11.glDrawArrays(GL11.GL_QUADS, 0, vertexCount);

GL20.glDisableVertexAttribArray(0);
GL30.glBindVertexArray(0);

But how can I say OpenGL that, the second VBO includes the normals?

And is this the right way to render my Cubes? Or is there a better?

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