Mathematical constructions, number systems. In 3D-graphics quaternions are used alongside vectors and matrices. One of the benefits of quaternions is that they overcome some rotational problems (known as gimbal locks) that are inherent to vectors and matrices.
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1answer
4k views
Orienting a model to face a target
I have two objects (target and player), both have Position (Vector3) and Rotation (Quaternion). I want the target to rotate and be facing right at the player. The target, when it shoots something ...
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2answers
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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, ...
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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));
...
10
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2answers
919 views
Why do people use quaternions?
I have been using them as a black box for a while, I'm just learning about of the maths but I'd just like some definitive answers to this question.
So far the only benefit I've come across personally ...
8
votes
2answers
564 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 ...
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6answers
3k views
Math topics for 3D graphics programming
I understand that the following math topics are required for 3D graphics programming. I have started doing some of them in my math course. Can someone point me in the direction of a resource that ...
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3answers
793 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?
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0answers
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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 ...
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1answer
260 views
Rotation matrices from Quaternion.Identity and -Quaternion.Identity are the same?
If I create a rotation matrix from an identity quaternion then it is the same as a creating it from a negative identity quaternion
Matrix m0 = ...
