GLSL: How to get pixel x,y,z world position?

Posted by Rookie on Stack Overflow See other posts from Stack Overflow or by Rookie
Published on 2011-02-04T15:13:50Z Indexed on 2011/02/04 15:25 UTC
Read the original article Hit count: 229

Filed under:

opengl

|

glsl

|

fragment-shader

I want to adjust the colors depending on which xyz position they are in the world.

I tried this in my fragment shader:

vec4 pos = vec4(gl_FragCoord); // get pixel position

but it seems that the z-coord is always towards my camera... how do i make the coords independent from my camera position/angle?

Edit: if it matters, heres my vertex shader:

gl_Position = ftransform();

Edit2: changed title, so i want world coords, not screen coords!

© Stack Overflow or respective owner

Related posts about opengl

Unity completely broken after upgrade to 12.10?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I am facing a very frustrating issue with my computer right now. I successfully upgraded to Ubuntu 12.10 this afternoon, but after the upgrade, the graphical user interface seems completely broken. To be more specific, I can not get the Unity bar to appear on the right. I have tried many things,… >>> More
OpenGL or OpenGL ES

as seen on Game Development - Search for 'Game Development'
What should I learn? OpenGL 4.1 or OpenGL ES 2.0? I will be developing desktop applications using Qt but I may start developing mobile applications in a few months, too. I don't know anything about 3D, 3D math, etc and I'd rather spend 100 bucks in a good book than 1 week digging websites and going… >>> More
OpenGL extension vs OpenGL core

as seen on Programmers - Search for 'Programmers'
I was doubting: I'm writing a cross-platform engine OpenGL C++, I figured out windows forces the developers to access OpenGL features above 1.1 through extensions. Now the thing is, on Linux, I know that I can directly access functions if the version supports it through glext.h and opengl version… >>> More
OpenGL ES 2/3 vs OpenGL 3 (and 4)

as seen on Game Development - Search for 'Game Development'
I have migrated my code from OpenGL ES 2/3 to OpenGL 3 (I added bunch of defines and abstract classes to encapsulate both versions, so I have both in one project and compile only one or another). All I need to change was context initialization and glClearDepth. I dont have any errors. This was kind… >>> More
LWJGL - Eclipse error [on hold]

as seen on Game Development - Search for 'Game Development'
When I try to run my lwjgl project, an error pops . Here is the log file: # A fatal error has been detected by the Java Runtime Environment: # EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x6d8fcc0a, pid=5612, tid=900 # JRE version: 6.0_16-b01 Java VM: Java HotSpot(TM) Client VM (14.2-b01 mixed… >>> More

Related posts about glsl

How to debug a GLSL shader ?

as seen on Stack Overflow - Search for 'Stack Overflow'
I need to debug a GLSL program but I don't know how to output intermediate result. Is it possible to make some debug traces (like with printf) with GLSL ? >>> More
How to update a uniform variable in GLSL

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi All, I am trying to get update the eye position in my shader from my appliaction but I keep getting error 1281 when I attempt this. I have no problems after the initialization just when i subsequently try to update the values. Here is my code: void GraphicsObject::SendShadersDDS(char vertFile… >>> More
GLSL check if fragment is on geometry

as seen on Stack Overflow - Search for 'Stack Overflow'
I am currently writing the positions of my geometry to the RGB channels of gl_FragColor and I would like to write 1.0 to the alpha channel if the fragment is part of geometry, and 0.0 if its empty. Is there a simple way to tell if a fragment is geometry or not? Maybe through gl_FragCoord.z? thanks >>> More
Implementing your own depth buffer with GLSL

as seen on Stack Overflow - Search for 'Stack Overflow'
I need a datastructure of the same size as the normal depth buffer and I need to be able to read from and write to it in a shader. Is this possible, and what does this datastructure look like? >>> More
Passing multiple Vertex Attributes in GLSL 130

as seen on Game Development - Search for 'Game Development'
(note this question is closely related to this one however I didn't fully understand the accepted answer) To support videocards in laptops I have to rewrite my GLSL 330 shaders to GLSL 130. I'm trying to do this but somehow I don't get vertex attributes to work properly. My 330 shaders look like… >>> More