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Type: Posts; User: FrankBoltzmann

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1. ## Thread: Ray origin through view and projection matrices

by FrankBoltzmann
Replies
3
Views
486

### So you are telling me to use (0,0,1) as my ray...

So you are telling me to use (0,0,1) as my ray direction and then (-1,-1,0) (-1,1,0) (1,-1,0) and (1,1,0) for the corner pixels (used for interpolation)? But then how would I do ray intersection with...
2. ## Thread: Ray origin through view and projection matrices

by FrankBoltzmann
Replies
3
Views
486

### Ray origin through view and projection matrices

Hi.

I have a fullscreen quad going from -1 to 1 in the X and Y axes, but staying in z=0. In the vertex shader I simply do...
gl_Position = vec4(inPos,1); ...so that it gets rasterized onto the...
3. ## Thread: When exactly does glBeginQuery set the counter to zero?

by FrankBoltzmann
Replies
17
Views
2,096

### Sorry, I was going to do this but I have been...

Sorry, I was going to do this but I have been busy with other parts of my experiment. Thank you for the results!

This pretty much finishes our debate: it is impossible to measure the delay.

I...
4. ## Thread: When exactly does glBeginQuery set the counter to zero?

by FrankBoltzmann
Replies
17
Views
2,096

### Do you mean doing a synchronized timestamp every...

Do you mean doing a synchronized timestamp every once in a while to check if the correlation is the same as before?

What I actually want to measure is as you said the duration from the command...
5. ## Thread: When exactly does glBeginQuery set the counter to zero?

by FrankBoltzmann
Replies
17
Views
2,096

### Response and explanation of my logic: ...

Response and explanation of my logic:

Exactly, let's say you capture GPU time at program start and it is A. You then capture CPU time when A is available, but there will always be a small...
6. ## Thread: When exactly does glBeginQuery set the counter to zero?

by FrankBoltzmann
Replies
17
Views
2,096

### Thanks for that quote from the spec, I couldn't...

Thanks for that quote from the spec, I couldn't find that anywhere! I think this should also be in the man page explaining the use of glBeginQuery...
7. ## Thread: When exactly does glBeginQuery set the counter to zero?

by FrankBoltzmann
Replies
17
Views
2,096

### Hi guys, thanks for the responses! My replies are...

Hi guys, thanks for the responses! My replies are in blue.
8. ## Thread: When exactly does glBeginQuery set the counter to zero?

by FrankBoltzmann
Replies
17
Views
2,096

### No experts on this? I was hoping to hear from...

No experts on this? I was hoping to hear from Alfonse or someone else :) too bad you can't tag forum members!
9. ## Thread: When exactly does glBeginQuery set the counter to zero?

by FrankBoltzmann
Replies
17
Views
2,096

### When exactly does glBeginQuery set the counter to zero?

Hi, I'm trying to determine the time it takes from the moment I call a glQueryCounter on the CPU and the moment it is actually executed on the GPU. The reference pages say that when you use...
10. ## Thread: FBOs and Viewports

by FrankBoltzmann
Replies
2
Views
1,151

### Hey, thanks for the reply. I was actually...

Hey, thanks for the reply. I was actually simplifying my question, because I didn't know about glBlitFramebuffer. What I really wanted to do was use one single full screen Framebuffer with multiple...
11. ## Thread: FBOs and Viewports

by FrankBoltzmann
Replies
2
Views
1,151

### FBOs and Viewports

Imagine I have a window of 1280x720 and I have an FBO of the same size. When drawing my scene, I draw it to my FBO using glViewport(640,360,1280,720) which is the top right corner of the window. Now...
12. ## Thread: Corrupted data during mapped buffer! (Uniform Buffer Objects)

by FrankBoltzmann
Replies
4
Views
1,137

### Each vec3 is considered a 3N, each float a 1N and...

Each vec3 is considered a 3N, each float a 1N and booleans are considered 1N as well. My layout is 3N, 1N, 3N, 1N and so on... and in the spec it says that when you use that kind of format, the 3N is...
13. ## Thread: Corrupted data during mapped buffer! (Uniform Buffer Objects)

by FrankBoltzmann
Replies
4
Views
1,137

### I thought so as well, but the bug was happening...

I thought so as well, but the bug was happening before I added that if statement! I was basically testing "spotlight" inside the shader and if it was "true" I would paint everything white, so...
14. ## Thread: Corrupted data during mapped buffer! (Uniform Buffer Objects)

by FrankBoltzmann
Replies
4
Views
1,137

### Corrupted data during mapped buffer! (Uniform Buffer Objects)

I didn't know whether to post this under beginners or not, but there's something wrong with my application when I try to map a buffer and write onto it. It's a really strange and specific bug. I have...

by FrankBoltzmann
Replies
0
Views
704

I have an SSBO that essentially stores all the world-space positions of each fragment created by the pipeline's rasterization of a scene from a specific fixed viewpoint. In each frame, I draw a...
16. ## Thread: GLSL concurrency + depth testing

by FrankBoltzmann
Replies
2
Views
1,104

### I found a way to create a sort of critical...

I found a way to create a sort of critical section:

uint closest = pixel[pixelIndex].closest_ptr;
uint actual_closest = pixel[pixelIndex].closest_ptr;
do {
closest = actual_closest;...
17. ## Thread: GLSL concurrency + depth testing

by FrankBoltzmann
Replies
2
Views
1,104

### GLSL concurrency + depth testing

Hi, I am implementing Per Pixel Linked Lists in OpenGL 4.3 using 2 SSBOs:

// -------------- PPLL Structures --------------- //
//
struct...

by FrankBoltzmann
Replies
3
Views
1,546

### Another question, but maybe I should make a new...

Another question, but maybe I should make a new topic since this one might be more advanced and interesting to answer: Is it possible to make a fragment shader output a list of vertices to go through...

by FrankBoltzmann
Replies
3
Views
1,546

### I would prefer a 1D array since I am doing...

I would prefer a 1D array since I am doing several interleaved linked lists, a 3D array would be allocating a fixed size for the linked lists if it was 1280x720xAVGDEPTHCOMPLEXITY. I need...

by FrankBoltzmann
Replies
3
Views
1,546

### SSBO access

Hi, this may be a rather specific question, but I need to access some structure on my fragment shader and write fragment information to it and then be able to read from that same structure on a...
21. ## Thread: Camera with fixed axis for yaw and vertical movement

by FrankBoltzmann
Replies
1
Views
1,576

### Camera with fixed axis for yaw and vertical movement

Hello,

I have a transformation matrix for a camera that consists of a Translation and a Rotation. The rotation was a product of yaw and pitch. To make the camera intuitive (at least for me) I...

by FrankBoltzmann
Replies
6
Views
3,065

### Isn't the point of deferred rendering to not...

Isn't the point of deferred rendering to not calculate all the lights per fragment since most fragments behind other fragments will be discarded? Using multiple passes to accumulate light is called...
23. ## Thread: Uniform Buffer Objects, dynamic sized arrays and lights

by FrankBoltzmann
Replies
21
Views
8,123

### I guess my final question is: If I'm allocating...

I guess my final question is: If I'm allocating 100 lights at initialization stage with glBufferData(100,NULL) and then using glMapBufferRange with invalidate bit flag, isn't it better to just use...
24. ## Thread: Uniform Buffer Objects, dynamic sized arrays and lights

by FrankBoltzmann
Replies
21
Views
8,123

### Ok so I should use...

Ok so I should use BufferData(100*sizeof(light),NULL) once at initialization stage and then only use glMapBufferRange with those flags? So in that link with the streaming techniques, I might have...
25. ## Thread: Uniform Buffer Objects, dynamic sized arrays and lights

by FrankBoltzmann
Replies
21
Views
8,123

### Yes but I'm not delivering a product, I'm doing...

Yes but I'm not delivering a product, I'm doing research so my purpose is to understand everything I can. It may take me a while to implement this due to all these discussions of optimization, but...
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