An array of numbers, symbols or expressions, arranged in row and columns. The numbers, symbols or expressions themselves are called elements or entries.
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 ...
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)
* ...
0
votes
0answers
30 views
Unity3D - Projection matrix camera frustum
I've used off centre projection to create a custom projection matrix for my camera.
When I run the game I can see the scene correctly in the game view but in the editor view the camera frustum is not ...
0
votes
1answer
51 views
Building View Matrix in Direct3D11
Am I doing it right? I converted this.
m_ViewMatrix = XMMatrixLookAtLH(XMLoadFloat3(&m_Position), lookAtVector, upVector);
to this one.
XMVECTOR vz = XMVector3Normalize( lookAtVector - ...
0
votes
2answers
111 views
OpenGL, objects disappear at a certain z distance
I'm writing a managed OpenGL library in C++, and I'm having a pretty annoying problem. Whenever I set an objects Z coordinate to -2.0 or lower, the object disappears. And at coordinates 0 through ...
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 ...
2
votes
0answers
34 views
Extract derived 3D scaling from a 3D Sprite to set to a 2D billboard
I am trying to get the derived position and scaling of a 3D Sprite and set them to a 2D Sprite.
I have managed to do the first part like this:
var p:Point = sprite3d.local3DToGlobal(new ...
2
votes
2answers
94 views
Rotating a child shape relative to its parent's orientation
When rotating a shape using a quaternion value I also wish rotate its child shape.
The parent and child shapes both start with different orientations but their relative orientations should always be ...
0
votes
1answer
57 views
Orthogonal projection and world transform
I'm reading about projection matrix. Needs of perspective projection is obvious, but I'm not sure about orthogonal projection. Because orthogonal projection effect looks possible with only world ...
2
votes
1answer
62 views
Camera closes in on the fixed point
I've been trying to create a camera that is controlled by the mouse and rotates around a fixed point (read (0, 0, 0)), both vertical and horizontal. This is what I've come up with:
camera.Eye = ...
0
votes
1answer
60 views
What's the standard location of a 3D clipping box?
The way I understand 3D rendering, polygons are transformed using several matrices, and they are then clipped if they are not inside a certain box, before projecting the box onto the screen. Before ...
2
votes
1answer
115 views
Does XNA 4 support 3D affine transformations for 2D images?
Looooong story short I'm essentially trying to code Mode 7 in XNA. Before I continue bashing my brains out in research and various failed matrix math equations; I just want to make sure that XNA ...
3
votes
1answer
86 views
D3DXMatrixDecompose gives different quaternion than D3DXQuaternionRotationMatrix
In trying to solve this problem, I tracked down the problem to the conversion of the rotation matrix to quaternion. In particular, consider the following matrix:
-0.02099178 0.9997436 -0.008475631 0
...
3
votes
2answers
120 views
How to derive euler angles from matrix or quaternion?
Currently working on steering behavior for my AI and just hit a little mathematical bump.
I'm in the process of writing an align function, which basically tries to match the agent's orientation with ...
2
votes
1answer
35 views
Problem with D3DXMatrixReflect
Currently I am trying to reflect a sky sphere into a flat piece of geometry which is acting as water. The sphere is very small, it follows the camera on all 3 axis and the z-buffer is turned off so it ...
