Tagged Questions
3
votes
1answer
102 views
Picking 3D with OpenGL ES 2
I'm trying to implement picking in my framework but I don't understand how I can do this.
I'm working with:
OpenGL ES 2.
GLM mathematic library.
What I have understand, picking can be made with ...
1
vote
0answers
59 views
Reconstructing Position from Linear Depth
In gBuffer (RGBA32F) I store a linear depth (camera space z position). Next I draw a full screen quad (two triangles) and I want
to reconstruct the position.
Vertex shader:
#version 420
...
2
votes
1answer
84 views
RGB to xyY color space conversion and luminance
The luminance calculated by following GLSL functions (fragment shaders - tonemap) has different value:
float GetLuminance (vec3 rgb)
{
return (0.2126 * rgb.x) + (0.7152 * rgb.y) + (0.0722 * ...
-1
votes
3answers
104 views
Directional light and matrix issues
I'm trying to implement basic directional lightning in OpenGL 3.3 by emulating the logic shown in this guide: http://www.arcsynthesis.org/gltut/Illumination/Tutorial%2009.html
I do not understand ...
4
votes
1answer
179 views
deferred rendering and point light radius
I use a common attenuation equation for point lights:
attenuation = 1 / kc + kl * d + kq * d^2.
I use deferred rendering so I need to know a light radius. An example light has following intensity: ...
4
votes
2answers
185 views
Defining an OpenGL unit
I have read that you can define your OpenGL unit by using glViewport.
As far as I understood if you use something like glViewport(0,0,600,600) then 1 OpenGL unit = 600 pixels. Now my problem is what ...
1
vote
1answer
153 views
Creating a frustum for culling in world-space glm matrices
I need to do frustum culling where the bounding boxes are in world-space to determine which entities get to be updated/drawn. I was trying to use the classic projection/view matrix plane extraction ...
2
votes
2answers
291 views
Bezier curve not drawn correctly
I'm trying to draw a bezier curve using 3 points. If I use the quadratic form:
I get this result:
And I believe it's correct.
Now since I need to draw it with a variable number of points, ...
2
votes
1answer
164 views
How to rotate a direction
I'm working a spotlight for my deferred renderer and I'm having trouble with matching the mesh to the visual representation of the light. Right now my mesh is a cone, the apex of the cone is at ...
2
votes
1answer
177 views
How to do perspective projection “parallax” but without changing the scale or offset of objects?
Hello everyone I have this problem that I have tried everything I could think of. The problem: I am making a 2D game with parallax effect but I am using 3d space so am not simulating the parallax but ...
4
votes
1answer
91 views
What OpenCL video cards (or FPGAs) features are needed for high speed multiplication?
I'm benchmarking some cryptographic related software and am looking for video cards that are better at parallel multiplication vs parallel addition.
Is there any prior work that would graph video ...
0
votes
1answer
113 views
Y Axis inverted on vertex output
I've got my project running and somehow it seems my vertex y components are inverted. 10 in the positive on Y goes down and 10 negative on the Y axis goes up.
I can't find anything with the ...
12
votes
1answer
192 views
Orthographic unit translation mismatch on grid (e.g. 64 pixels translates incorrectly)
I am looking for some insight into a small problem with unit translations on a grid.
Update and Solved
I solved my own issue. See below for details. Everything in this part of the post turned out to ...
2
votes
2answers
104 views
setting the position in different resolution
I have a normal game window which is 640*480, and everything is fine, but when I try to maximize the window, the objects translate to different positions on the screen, for example If I have a circle ...
2
votes
2answers
363 views
Quaternion based rotation and pivot position
I can't figure out how to perform matrix rotation using Quaternion while taking into account pivot position in OpenGL.What I am currently getting is rotation of the object around some point in the ...
