# Search:

Type: Posts; User: Lee_Jennifer_82

Page 1 of 3 1

1. ## Thread: Calculating texture coordinates

by Lee_Jennifer_82
Replies
4
Views
193

### Thank you, GClements. But I've one question, the...

Thank you, GClements. But I've one question, the other softwares like Maya etc. definitely generate texture coordinates from vertex coordinates, isn't it? What's the underlying principle of...
2. ## Thread: Calculating texture coordinates

by Lee_Jennifer_82
Replies
4
Views
193

### Calculating texture coordinates

Hello, I have vertex data and face indices which I've read from a file. I'd like to get the object texture-mapped but texture coordinates are not available in the file. I know that texture...

by Lee_Jennifer_82
Replies
2
Views
150

### Thank you so much! Now I understand. Actually...

Thank you so much! Now I understand. Actually 'theta' and 'phi' are angles of projection with the x and y axes respectively.

by Lee_Jennifer_82
Replies
2
Views
150

Suppose, I have defined a model view matrix as follows:

where theta and alpha are some angles less that 90 degree.
What transformation actually this matrix does? Is it about some...

by Lee_Jennifer_82
Replies
3
Views
232

### Thank you! But sometimes models (objects) go...

Thank you! But sometimes models (objects) go through local transformation like rotation, scaling etc, before camera or view transformation, but in this case lights only need to go through camera/...

by Lee_Jennifer_82
Replies
3
Views
232

### Light position

Suppose, I've defined models/ objects and light position in my program. Models will undergo modelview transformation and light position will undergo view transformation. Is it right?
Sometimes I...

by Lee_Jennifer_82
Replies
3
Views
214

### But when red is at top, shouldn't be the red...

But when red is at top, shouldn't be the red component more prominent? The resulting color (0.5, 0.75, 0.25) shows green is prominent here.

by Lee_Jennifer_82
Replies
3
Views
214

I was just taking a look at the following tutorial:

http://www.opengl-tutorial.org/intermediate-tutorials/tutorial-10-transparency/

But a bit confused at the end. It tries to draw a red...

by Lee_Jennifer_82
Replies
6
Views
405

### Ok, clipping is performed in homogeneous...

Ok, clipping is performed in homogeneous coordinate to avoid division by zero. But can't this also happen during perspective division? I'm a bit confused.

by Lee_Jennifer_82
Replies
6
Views
405

### Hello GClements, thank you so much for the...

Hello GClements, thank you so much for the clarification. Now much clearer:at clipping stage perspective transformation doesn't have meaning.It only have meaning after perspective division. Now if...

by Lee_Jennifer_82
Replies
6
Views
405

Hello, I need some clarification about clipping. It is said clipping is done before the perspective division and the view volume is within the following boundary

1)Does it mean clipping is...
12. ## Thread: How to view the bounding box of the view volume

by Lee_Jennifer_82
Replies
14
Views
907

### Please ignore my poor knowledge. Is it that...

Please ignore my poor knowledge. Is it that viewplane is the near plane in perspective projection?
13. ## Thread: How to view the bounding box of the view volume

by Lee_Jennifer_82
Replies
14
Views
907

### Thanks for the explanation. I have another simple...

Thanks for the explanation. I have another simple question:suppose I'd like to see the same object using orthographic as well as perspective projection. My eye is at the same distance suppose (0, 0,...
14. ## Thread: How to view the bounding box of the view volume

by Lee_Jennifer_82
Replies
14
Views
907

### Hello, GClements, thank you so much for the...

Hello, GClements, thank you so much for the explanation.

Does it always hold for perspective projection that near and far planes both should be in front of the eye? Or there is some...

by Lee_Jennifer_82
Replies
0
Views
190

I was just looking at Angel's book about derivation from Frustum to Perspective

it is written

Now ,top derived as follows:

Should not be top defined as follows:
16. ## Thread: Question when number of vao more that one

by Lee_Jennifer_82
Replies
1
Views
217

### Question when number of vao more that one

I have two vertex array objects. I defined as follows:

My question is, is it okay to define two vertex array objects like these for drawing two objects?

Because when I use the...
17. ## Thread: How to view the bounding box of the view volume

by Lee_Jennifer_82
Replies
14
Views
907

### But why it should have the same effect.Isn't the...

But why it should have the same effect.Isn't the near plane at the back of camera in this case? What did you mean by overdraw, drawing two objects one behind another? Will then this change be...
18. ## Thread: How to view the bounding box of the view volume

by Lee_Jennifer_82
Replies
14
Views
907

### I figured it out. there was something wrong in...

I figured it out. there was something wrong in the shader. I used some scale factor which was producing wrong result. But I swapped near and far plane and that didnot have effect on the output. Could...
19. ## Thread: How to view the bounding box of the view volume

by Lee_Jennifer_82
Replies
14
Views
907

### Ok, thanks. Now I am again asking the following...

Ok, thanks. Now I am again asking the following question.

I've drawn a cube at the origin. Now I've called the ortho function from glm library as follows:

glm::mat4 projection_matrix =...
20. ## Thread: Does the image always form at the eye position?

by Lee_Jennifer_82
Replies
0
Views
151

### Does the image always form at the eye position?

I've the following few questions:

Does the default image always form at the eye position?
In some books, eye position and view reference point mentioned as the same? Is it true only for default...
21. ## Thread: How to view the bounding box of the view volume

by Lee_Jennifer_82
Replies
14
Views
907

### How to view the bounding box of the view volume

Hello, I'd like to draw the bounding box after applying the following projection matrix:

glm::ortho(-10.0f, 10.0f, -10.0f, 10.0f, 1.0f, 10.0f);

How can I find the coordinates of the bounding...
22. ## Thread: reshape function for correct proportion between window and viewport

by Lee_Jennifer_82
Replies
5
Views
416

### It works Alfonso, my code was wrong, aspect...

It works Alfonso, my code was wrong, aspect should be Width/ Height.
Thank you!
23. ## Thread: Can anyone explain me the attched picture from Angel's book

by Lee_Jennifer_82
Replies
6
Views
446

### Thank you both Dark Photon and GClements for...

Thank you both Dark Photon and GClements for trying to help me out. I understand but still a bit confused. I understand znear is smaller near the eye and perspective division produces the result at...

by Lee_Jennifer_82
Replies
6
Views
386

### Hello GClements, I'm still unclear. It would be...

Hello GClements, I'm still unclear. It would be very kind of you to explain with respect to the example mentioned below:
Camera at origin, object at origin and ortho function looks like follows:

...
25. ## Thread: reshape function for correct proportion between window and viewport

by Lee_Jennifer_82
Replies
5
Views
416

### I used the following for orthographic projection,...

I used the following for orthographic projection, but it didn't work. What's wrong?

my reshape function is as follows:
Results 1 to 25 of 62
Page 1 of 3 1