The circular movement of an object around a specific axis.
4
votes
2answers
1k views
Move sprite in the direction it is facing?
I'm using Java/Slick 2D. I'm trying to use the mouse to rotate the sprite and the arrow keys to move the sprite. I can get the sprite to rotate no problem, but I cannot get it to move in the direction ...
9
votes
2answers
2k views
How can I rotate about an arbitrary point in 3D (instead of the origin)?
I have some models that I want to rotate using quaternions in the normal manner, except instead of rotation about the origin, I want it to be offset slightly. I know that you don't say, in 3d space, ...
2
votes
3answers
534 views
How to Align Gun with Bullets
I have a top-down 2D shooter. I have an image of a player holding a gun, that rotates to face the mouse. Please note that the gun isn't a separate image tethered to the player, but rather part of the ...
3
votes
3answers
6k views
How can I rotate a camera about it's target point?
I'm drawing a scene where the camera freely moves about the universe. The camera class keeps track of the view (or look at) point, the position of the camera, and the up vector. These vectors/points ...
3
votes
1answer
840 views
Turning a sprite such that it rotates in the direction that's most efficient
I have a sprite that moves from waypoint to waypoint. It turns to face its velocity vector, but not instantly (there's a rotation speed).
The problem I'm having is, from one direction to another, the ...
3
votes
3answers
467 views
How to calculate origin and position of a weapon which should be “in hands”?
I'm currently stuck with my game, which is from the top perspective. I'm currently using these sprites for player: (using the second at the top):
And here's what I use for my gun
My problem is ...
6
votes
1answer
440 views
How To Approach 360 Degree Snake
I've recently gotten into XNA and must say I love it. As sort of a hello world game I decided to create the classic game "Snake". The 90 degree version was very simple and easy to implement. But as I ...
3
votes
1answer
1k views
Moving a rotated model in XNA
This seems like a simple problem with an equally simple solution that is invisible to me.
I have a model that spawns at the origin and looks at my player model wherever it goes.
I would like it to ...
1
vote
3answers
219 views
Inverting matrix then decomposing gives different quaternion than decomposing then inverting the quat
I'm getting different signs when I convert a matrix to quaternion and invert that, versus when I invert a matrix and then get the quaternion from it:
Quaternion a = Quaternion.Invert(getRotation(m));
...
0
votes
1answer
577 views
rotate sprite and shooting bullets from the end of a cannon [duplicate]
Possible Duplicate:
How to Align Gun with Bullets
Hi all i have a problem in my Andengine code,
I need , when I touch the screen, shoot a bullet from the cannon (in the same direction of ...
0
votes
2answers
416 views
CubeRealm OpenGL rotation problems, need help. :\
I'm totally new to OpenGL and I'm working on a Sandbox game called CubeRealm. My problem you see is rotation. I've got it in my head that to rotate the 'camera' I just rotate all the scene by the ...
11
votes
4answers
2k views
How to rotate blocks in tetris
I have a gameboard grid which is 20 rows high and 10 columns wide with the origin (0,0) being in the top left hand corner.
I have a tetrimino in play, which is composed of four blocks.
I have the x,y ...
8
votes
2answers
569 views
Arbitrary Rotation about a Sphere
I'm coding a mechanic which allows a user to move around the surface of a sphere. The position on the sphere is currently stored as theta and phi, where theta is the angle between the z-axis and the ...
6
votes
2answers
658 views
How to implement friction in a physics engine based on “Advanced Character Physics”
I have implemented a physics engine based on the concepts in the classic text Advanced Character Physics by Thomas Jakobsen. Friction is only discussed very briefly in the article and Jakobsen himself ...
6
votes
2answers
1k views
How do I rotate a structure of hexagonal tiles on a hexagonal grid?
My 2D isometric game uses a hexagonal grid map. In reference to the image below, how do I rotate the light blue hexagon structures by 60 degrees around the pink hexagons?
EDIT:
Main hex is (0,0). ...
4
votes
1answer
1k views
How do I rotate a sprite so that it is 'pointing' in the direction it is moving
I have a sprite, e.g a missile, heading in a certain direction (using a velocity vector).
How do I figure out its how much to rotate it so that it gets drawn 'pointing' in the direction it is ...
3
votes
3answers
795 views
How to keep my Quaternion-using FPS camera from tilting and messing up?
I am using an FPS-like camera, and it uses quaternions. But, whenever I try looking up and then sideways, it tilts, and sometimes it can turn upside down. How can I fix this?
1
vote
1answer
249 views
How to make a stack stable? Need help for an explicit resting contact scheme (2-dimensional)
Previously, I struggle with the sequential impulse-based method I developed. Thanks to jedediah referring me to this paper, I managed to rebuild the codes and implement the simultaneous impulse based ...
1
vote
1answer
460 views
Rotate triangle so that its tip points in the direction of the point on the screen that we last touched
OpenGL ES - Android.
Hello all, I am unable to rotate the triangle accordingly in such a way that its tip always points to my finger.
What i did : Constructed a triangle in by GL.GL_TRIANGLES. Added ...
1
vote
2answers
599 views
Transformation order when dealing with Meshes
I have created a player model out of primitive types. To do this I have created a Model class and Component (mesh) class. Each model consists of one or more components my problems start when you have ...
8
votes
4answers
226 views
Keeping rotation between two objects
In my XNA game I have two objects that collide. When the first object collides with the other it is able to latch on to it and move it about the world. I am having a problem with the math here (Math ...
4
votes
2answers
531 views
I need help with 2D collision response (of stacking rotating polygons, with friction and gravity, for a game)
Hi I am looking for suggestions on how to write a collision response for game programming purpose (so not a scientific simulation). I am dealing with 2D polygons that are rotating, and I want them to ...
2
votes
2answers
556 views
How can I make a sprite move in the direction it's facing using radians?
I am using PGELua for the PlaystationPortable. I would just like to know how to make a 2D sprite move in the direction that the sprite is facing.
When the sprite is blitted to the screen it should ...
1
vote
0answers
38 views
How to set object's / node's absolute rotation correctly?
Usually when I want to rotate an object/node in my Ogre scene I call the node's rotate() method. That rotates the node locally relative to it's current rotation. So for example, when I start with 0 ...
1
vote
1answer
122 views
Camera wont stay behind model after pitch, then rotation
I have a camera position behind a model. Currently, if I push the left thumbstick making my model move forward, backward, or strafe, the camera stays with the model. If I push the right thumbstick ...
1
vote
2answers
562 views
Matrix rotation of a rectangle to “face” a given point in 2d
Suppose you have a rectangle centered at point (0, 0) and now I want to rotate it such that it is facing the point (100, 100), how would I do this purely with matrix math?
To give some more specifics ...
1
vote
2answers
2k views
XNA advanced rotation 3D
I'm able to rotate any model with any angle I want, where I can not rotate my model around a given point.
e.g: My model rotates from the origin assigned in its .fpx file. I want it to rotate related ...
0
votes
1answer
343 views
Joystick example problem for android 2D
I've searched all over the web for an answer to this, and there are simular topics but nothing works for me, and I have no Idea why. I just want to move my sprite using a joystick, since I'm useless ...
-2
votes
3answers
241 views
How to rotate to a target position over time
I know how to do rotations to vectors, but how do I rotate over time?
For instance say I made a function
RotateTo(vec2 iPosition, float iTime);
so it rotates to iPosition over iTime - how would ...
