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Apr
23
comment Quaternion not giving correct value back. What am I doing wrong here?
(1) Your expected value is incorrect; and (2) you are not displaying enough decimals in your actual result, as you will need to show 4 (probably) to get sufficient precision for this test. Repeat three times: "Quaternions are NOT vectors.". Then repeat three more times "Degrees are 57 times smaller than radians."
Apr
14
awarded  Nice Answer
Apr
4
comment Correct way to integrate scaled axis angular velocity into a quaternion
What is the method "Quaternion.mul" doing, exactly?
Mar
30
comment Accelerated movement in a specific time to a specific point
Also, be sure to use average values for velocity over each time interval when calculating displacement, not initial or final. That is the third most common source of error.
Mar
30
comment Accelerated movement in a specific time to a specific point
In physics, only unit-less quantities are eligible to be scalars. Since displacement and acceleration are not unit-less, one must sign them properly as vectors (or in some cases as pseudo vectors, but that distinction is not relevant here), even if only 1D, in order to obtain consistently correct results.
Mar
30
comment Accelerated movement in a specific time to a specific point
The most common errors are (1) the units are incorrect; or (2) the sign on an initial value is incorrect. Remember that all values (even time, in a sense) are vectors, even if only positive and negative along a number line. Have you properly defined your displacement, velocity, and acceleration vectors with the same direction convention? Draw a diagram if you are not sure, and ensure that a positive velocity increases a positive displacement, and that a positive acceleration increases a positive velocity. Ensure you have a consistent origin convention.
Mar
30
comment Vector math to calculate the rotation and drift of a tectonic plate?
Any movement of your plates, in general, will deform the plates such that you will require defined "mid-oceanic ridges" where plate material is produced, and subduction zones where plate material is consumed. Both processes perform work, of course, which must obey the Law of Conservation of Energy based on (very, very) slow thermal cooling of the core.
Mar
30
comment Accelerated movement in a specific time to a specific point
Rearrange equation (3) from the duplicate above to obtain: u = (d / t) - (a t) / 2.
Mar
30
comment Accelerated movement in a specific time to a specific point
Possible duplicate of How to implement deceleration and stopping over a certain distance
Mar
27
comment How to calculate distance of travel needed get achieve speed x?
Your physics and math is correct according to your model; but your model is not particularly realistic. A better model would calculate drag resistance as the sum of a linear term in speed (dominating at slow speeds) and a quadratic term in speed (dominating at higher speeds). Playing with the two constants would better illustrate the deficiencies of the constant deceleration assumption you have made.
Mar
23
comment what is an elegant way to add a border to a hexagonal grid
Check out my HexGrid Utilities library for various ideas: hexgridutilities.codeplex.com
Mar
16
comment How to get correct quaternion value from real world to screen?
Matrix/vector formulas as written by mathematicians are right-associative; as written by programmers are (typically) left-associative.
Mar
14
comment How to get correct quaternion value from real world to screen?
Switching of axes in a result is a sign that you have commuted two non-collinear rotations; are you sure that you have performed the operations in the correct order? Also note that in a sense, an individual quaternion comprises only half of a transformation. It must be combined with its complex conjugate (same as the inverse only for normalized quaternions) as here: v' = q v q*. I don't see that happening in your equations, though perhaps they are abbreviated.
Mar
14
comment What is easiest way to move towards and along the edge on a hex grid?
It might also help OP to point out the invariant satisfied by cube coordinates: x + y + z == 0. Because of this invariant it is never necessary to store all three; the third can always be reconstructed from the other two.
Mar
12
comment How to get correct quaternion value from real world to screen?
Perhaps you should just stick to homogenous coordinates with augmented matrices as here (en.wikipedia.org/wiki/…). Arguable a bit less efficient for some operations than quaternions, but much more intuitive.
Mar
11
comment calculating the weights for direction vectors to a target
The direction vectors must be normalized first of course - obvious to you and I but perhaps not to OP.
Feb
21
awarded  Yearling
Feb
10
comment What Is Vector Math?
@TylerTheHero: If you have an aptitude, you can probably get a handle on these basics in 12 months of diligent study - and it is all relevant to your high school courses. You can get assistance here for any and all questions, on specific problems, that you encounter. Just choose the right stack for each question.
Feb
10
comment What Is Vector Math?
Home study program to get started: Learn enough Calculus, Algebra and Physics to understand (1) how and why matrices of Homogenous Coordinates work (2D and 3D) and (2) why the acceleration required (in an Inertial Frame) for a circular orbit is towards the centre of the circle. If you can do that on your own you are in a position to write a simple game, and to learn everything else you will need as you encounter it.
Feb
10
comment What Is Vector Math?
Basic Linear Algebra should be covered in the final year of High School (in North America at least). First Year Algebra at University will go into more depth, especially in regards matrices of Homogenous Coordinates (for Graphics Transformations). First year Mechanics will cover most of the basic Physics required, which will assume you are familiar with first year Calculus as well as Algebra. All of this material can readily be learned from material freely available on the Internet, for anyone with aptitude and incentive.