A mathematical concept that can be used to express position, direction or velocity and which can simplify or outright trivialise spatial problems.
3
votes
2answers
58 views
3D rotation matrices deform object while rotating
I'm writing a small 3D renderer (using an orthographic projection right now).
I've run into some trouble with my 3D rotation matrices. They seem to squeeze my 3D object (a box primitive) at certain ...
3
votes
1answer
98 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 ...
0
votes
1answer
48 views
how can i get rotation vector from matrix4x4 in xna?
i want to get rotation vector from matrix to realize some parent-children system for models.
Matrix bonePos = link.Bone.Transform * World;
Matrix m = Matrix.CreateTranslation(link.Offset)
* ...
3
votes
2answers
55 views
Determining a point that reached another point
I have two points, one is moving and one is stationary. I would like to know if the moving point has reached that point or not. I tried to calculate the distance between two vectors and the distance ...
3
votes
1answer
55 views
How to make an object stay relative to another object
In the following example there is a guy and a boat. They have both a position, orientation and velocity.
The guy is standing on the shore and would like to board. He changes his position so he is ...
1
vote
2answers
64 views
Billboarding + aligning with velocity direction
I'm working on a particle system where I'm orientating the billboard using the inverted orientation matrix of my camera. This works quite well and my quad are rotated correctly towards the camera.
...
6
votes
2answers
146 views
Rotate a vector
I want my first-person camera to smoothly change its viewing direction from direction d1 to direction d2. The latter direction is indicated by a target position t2.
So far I have implemented a ...
0
votes
0answers
70 views
C++ Directx 11 D3DXVECTOR3 doesn't allow me to devide it
If i have a simple vector3 like this:
D3DXVECTOR3 inversevector = D3DXVECTOR3( (pos+lookat_pos));
It works perfect!
But let's say i wanted to multiply it by:
Speed*(float) timeHandler.GetDelta()
...
5
votes
1answer
155 views
Moving in a diamond - enemy gets stuck
I have an enemy that I would like to move as follows:
Start at (0, 200, 0)
Move to (200, 0, 0)
Move to (0, -200, 0)
Move to (-200, 0, 0)
Move to start point, repeat as long as it remains active.
...
-1
votes
4answers
91 views
What is a good starting project to get up to speed with vectors and vector math? [closed]
I have been getting into games programming recently. However, all I have made so far (in order) is Snake, Breakout and Tetris.
I want to take on a bigger project, and some research has led me to ...
2
votes
1answer
89 views
How do I implement a selectable world map?
I want to have a selectable map of the world, preferably zoomable, in a cocos2d project. When I tap on a country, I want that country to be selected so that I can perform some other operations with ...
1
vote
1answer
148 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
1answer
86 views
Unity: parallel vectors and cross product, how to compare vectors
I read this post explaining a method to understand if the angle between 2 given vectors and the normal to the plane described by them, is clockwise or anticlockwise:
public static AngleDir ...
1
vote
1answer
77 views
Viewport.Unproject - Checking if a model intersects a large sprite
Let's say I have a sprite, drawn like this:
spriteBatch.Draw(levelCannons[i].texture, levelCannons[i].position, null, alpha, levelCannons[i].rotation, Vector2.Zero, scale, SpriteEffects.None, 0);
...
3
votes
1answer
99 views
Limit rotation heading by cone/angle
What is a fast way of limiting the heading vector to a certain angle so that it turns in greater distance relative to the limit.
A smaller cone/angle should make the object take a far bigger curve to ...
