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Type: Posts; User: wmelgaard

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1. ## Thread: Can't reshape subwindow

by wmelgaard
Replies
2
Views
236

Your answer sounds like a style issue. Within my project, "windowheight" is a computed number. For the test problem, I merely toggled between two heights. In practice, "windowheight" can be any one...
2. ## Thread: 3D Poisson distribution

by wmelgaard
Replies
3
Views
737

### Assume that your box is bounded by [0,0,0; 0,0,1;...

Assume that your box is bounded by [0,0,0; 0,0,1; 0,1,0; 0,1,1; 1,0,1; 1,1,1]. Compute your point [x,y,z] where (0 <= x <= 1); (0 <= y <= 1); (0 <= z <= 1) and plot your point within your cube. ...
3. ## Thread: 3D Poisson distribution

by wmelgaard
Replies
3
Views
737

### I don't understand what you are trying to do. ...

I don't understand what you are trying to do.
Are you using a random number generator with a poisson distribution to pick points off an OpenGL cube?
Or are you plotting points within that cube?
4. ## Thread: Can't reshape subwindow

by wmelgaard
Replies
2
Views
236

### Can't reshape subwindow

I am running Debian Stable (Jessie), with GLU1.3, and am trying to reshape a subwindow.
The following program writes a subwindow in the top, left corner of the main window. If you left-click on that...
5. ## Thread: gluLookAt & depth culling

by wmelgaard
Replies
1
Views
402

### gluLookAt & depth culling

I have a model 0.0 < z < 30.0. The default gluLookAt(0,-100,0, 0,0,0, 0,1,0); looks at the bottom of the model. If I rotate the model, the bottom of the model occludes anything above it.
If I...
6. ## Thread: Graphics disappear under certain geometries.

by wmelgaard
Replies
2
Views
764

### see...

see https://www.opengl.org/sdk/docs/man3/xhtml/glCullFace.xml
The default is to cull a polygon whose back is to the viewer.
Add the disable, and those faces should reappear

by wmelgaard
Replies
0
Views
517

### glutDewstroyWindow cleanup

My situation is that I have a subwindow in mainwindow which creates another subwindow in mainwindow. The second subwindow provides a template for inputting data. Upon completion of data entry, I...

by wmelgaard
Replies
3
Views
976

### The window was created with subWindow =...

The window was created with
subWindow = glutCreateSubWindow(mainWindow, margin, margin, width, height);
glViewport(0, 0, (GLsizei) width, (GLsizei) height);

Basically, I want to change...

by wmelgaard
Replies
3
Views
976

### resizing subwindow

I have an existing subwindow that is to be replaced by a different one.
Should I destroy the original and then create a new one, or merely change the size of the existing one?
How do I change the...
10. ## Thread: Identifying a specific vertex

by wmelgaard
Replies
0
Views
557

### Identifying a specific vertex

If I mouse-click on s specific pixel, that will give me the x & y of the mouse, which is the projected location of the vertex which drew that pixel. Similarly, glReadPixels(x, y, 1, 1,...

by wmelgaard
Replies
4
Views
2,069

### That works. Problems solved. Thanx. FYI for...

That works. Problems solved. Thanx.

given

glMatrixMode(GL_PROJECTION);
glOrtho(xmin, xmax, ymin, ymax, zmin, zmax);
...

by wmelgaard
Replies
4
Views
2,069

### Changing the 0 to 1 helps. I misinterpreted the...

Changing the 0 to 1 helps. I misinterpreted the glReadPixels() definition to be (target) + width & (target) + height.
Leaving the glutSwapBuffers() where it is, I get z = 0.25194 and bgr = 0. Since...

by wmelgaard
Replies
4
Views
2,069

The following program gives a value of (some random number) for the red point, but 0.0000 for the z-value of the point.
How do I get a return of z != 0.0000, given that the point is located at 50,...
14. ## Thread: glOrtho in GL_PROJECTION vs GL_MODELVIEW?

by wmelgaard
Replies
2
Views
965

### From the tutorial, "do you want to move the...

From the tutorial, "do you want to move the camera in one direction, or move the object in the opposite direction?" All of the examples in Chapter 3 move the model. Nate Robins' robot arm is drawn...
15. ## Thread: glOrtho in GL_PROJECTION vs GL_MODELVIEW?

by wmelgaard
Replies
2
Views
965

### glOrtho in GL_PROJECTION vs GL_MODELVIEW?

I have a model xmin = -264.000000, xmax = 384.000000; ymin = -263.942993, ymax = 330.480591; zmin = 673.751099, zmax = 1345.000000
If I include glOrtho((xmin -margin), (xmax +margin), (ymin...
16. ## Thread: glTranslate( 0, 0, something ) ineffectual on VBO

by wmelgaard
Replies
8
Views
3,020

### Back to basics, I have recently learned that my...

Back to basics, I have recently learned that my push, transform and pops affect the transformation matrix, not the contents of the framebuffer. You say, "well, duh?"

Google NASTRAN for what I am...
17. ## Thread: glTranslate( 0, 0, something ) ineffectual on VBO

by wmelgaard
Replies
8
Views
3,020

### Wow. I am mostly self taught, and my background...

Wow. I am mostly self taught, and my background is as a structural engineer (PE), and incidentally as a computer programmer. I have the Red Book; I should probably get a copy of the Blue Book rather...
18. ## Thread: glTranslate( 0, 0, something ) ineffectual on VBO

by wmelgaard
Replies
8
Views
3,020

### I am writing an open source version of NASTRAN....

I am writing an open source version of NASTRAN. Think of it as a CAD model undergoing computer analysis. My test file is from a real life project that has 10,000 points. My current objective is to...
19. ## Thread: glTranslate( 0, 0, something ) ineffectual on VBO

by wmelgaard
Replies
8
Views
3,020

### My objective is to rotate the entire model about...

My objective is to rotate the entire model about the center of the second VBO.
I am running Debian oldstable

KDE reports OpenGL version 2.1 Mesa 7.7.1, and GLX version 1.4 Mesa. I understand that...
20. ## Thread: glTranslate( 0, 0, something ) ineffectual on VBO

by wmelgaard
Replies
8
Views
3,020

### glTranslate( 0, 0, something ) ineffectual on VBO

I constructed two widgets, one centered on z =0, and another at z = offset, and wrote them both to VBO[1] and VBO[2].

glMatrixMode(GL_MODELVIEW);
glColor( 1, 0, 0 );
glPushMatrix();...
21. ## Thread: glTranslate & glRotate deprecated

by wmelgaard
Replies
1
Views
1,198

### glTranslate & glRotate deprecated

that glTranslate and glRotate are being deprecated in favor of OpenGL Mathmatics (GLM).
This may fine and...
22. ## Thread: Triangulating a surface constructed by 3D curves

by wmelgaard
Replies
5
Views
3,051

### Again without having seen your data, it sounds...

Again without having seen your data, it sounds like the same problem as meshing a Finite Element Analysis (FEA) model. The Finite Element Method Its Basis And Fundamentals , by Ziendiewicz, Taylor &...
23. ## Thread: Simple iOS 3D drawing app

by wmelgaard
Replies
1
Views
1,830

### A few tutorials are nice, but if you really want...

A few tutorials are nice, but if you really want to get into OpenGL, you need "The Red Book" OpenGL Programming Guide, available from your favorite book seller. This forum is not an adequate...
24. ## Thread: Triangulating a surface constructed by 3D curves

by wmelgaard
Replies
5
Views
3,051

### The example that I provided (creating a sphere...

The example that I provided (creating a sphere from a single triangle strip) in this forum sounds close to what you are trying to do.
assume:
float curve[n][npoints][3]; // this assumes that all...

by wmelgaard
Replies
4
Views
3,520