Tagged Questions
1
vote
2answers
188 views
Render rotated rectangle inside other rectangle bounds using Libgdx
I have this code to generate a red rectangle inside a grey rectangle:
new Rectangle(grey_rectangle_position_x, Game.SCREEN_HEIGHT/2-Rectangle.height/2,0);
This code makes the following:
Now, I ...
0
votes
1answer
102 views
How do I apply 2 rotations about different points to a single primitive using OpenGL
I'm working on a 2D top-down shooter game that has a rotation feature like Realm Of The Mad God such that if you press e the camera rotates around the character in a clockwise direction and q rotates ...
0
votes
1answer
488 views
Rotating Objects in OpenGL: glRotate or Quaternions?
I'm coding my first engine and I'm trying to have performance in mind since I'll probably use it for mobiles, and I have this question, should you use glRotate or Quaternions for rotating objects in ...
0
votes
1answer
143 views
rotate sphere horizontally around another sphere
I currently have an earth and a moon. What I'm trying to achieve is to have the moon physically rotate around the earth horizontally along the equator along a circular path.
moonAngle = ...
3
votes
2answers
241 views
How is the gimbal locked problem solved using accumulative matrix transformations
I am reading the online "Learning Modern 3D Graphics Programming" book by Jason L. McKesson
As of now, I am up to the gimbal lock problem and how to solve it using quaternions.
However right here, ...
0
votes
2answers
445 views
Rotating a Quad around it center
How can you rotate a quad around its center?
This is what im trying to do but it aint working:
GL11.glTranslatef(x-getWidth()/2, y-getHeight()/2, 0);
GL11.glRotatef(30, 0.0f, 0.0f, ...
3
votes
2answers
394 views
How to rotate camera centered around the camera's position?
Currently I am using gluLook at like so:
gluLookAt(position.x, position.y, position.z,
viewPoint.x, viewPoint.y, viewPoint.z,
upVector.x, upVector.y, upVector.z);
with the ...
1
vote
2answers
426 views
Rotating 2D Object
Well I am trying to learn openGL and want to make a triangle move one unit (0.1) everytime I press one of the keyboard arrows. However i want the triangle to turn first pointing the direction where i ...
2
votes
3answers
314 views
OpenGL Get Rotated X and Y of quad
I am developing a game in 2D using LWJGL library.
So far I have a rotating box. I have done basic Rectangle collision, but it doesn't work for rotated rectangles.
Does OpenGL have a function that ...
2
votes
1answer
411 views
Rotating To Face a Point
I am trying to rotate a line to point to the mouse's world coordinates (rather where the mouse lies on the plane where y=0).
I am running into a couple of problems though:
Whilst it follows the ...
2
votes
1answer
296 views
Finding a suitable axis-angle to avoid gimbal lock
In OpenGL the camera faces the -z axis with the +y axis pointing up. I am using quaternions to represent the orientation of my objects (which works well) and am trying to do the same for the camera. I ...
0
votes
1answer
159 views
Earth's rotation along it's axis
I've modeled an earth using an sphere. I can rotate it using glRotatef function around z axix by incrementing the angle. How do I simulate earth's movement which looks like 23.5Degree around Z axis? ...
0
votes
1answer
570 views
Camera Rotation (for mouse look) with LookAt does not work as expected (Local/Global)
My code for rotating my 3D fps camera isn't working as expected.
I expect that the X-axis does rotate with the Y-axis, but it ain't so.
I made some pictures to explain it better, I think its doing ...
1
vote
1answer
291 views
OpenGL: Rotating cannon about non-centre position?
So I have a "cannon" object (basically a long cylinder) and I want to be able to control its angle. The code I have now is:
glPushMatrix()
glTranslatef(self.position.x,2.5,self.position.z)
...
5
votes
3answers
624 views
Rotate a particle system
Languages / Libraries in use: C++, OpenGL, GLUT
Okay, here's the deal.
I've got a particle system which shoots out alpha blended textures to produce a flame. The system only keeps track of very ...
