Search Results
Search type | Search syntax |
---|---|
Tags | [tag] |
Exact | "words here" |
Author |
user:1234 user:me (yours) |
Score |
score:3 (3+) score:0 (none) |
Answers |
answers:3 (3+) answers:0 (none) isaccepted:yes hasaccepted:no inquestion:1234 |
Views | views:250 |
Code | code:"if (foo != bar)" |
Sections |
title:apples body:"apples oranges" |
URL | url:"*.example.com" |
Saves | in:saves |
Status |
closed:yes duplicate:no migrated:no wiki:no |
Types |
is:question is:answer |
Exclude |
-[tag] -apples |
For more details on advanced search visit our help page |
Mathematics questions deal with the arithmetic, geometry, calculus, formulae and other calculations used in the development of a game.
1
vote
Accepted
Get all points of a parabola
In general, there is no parabola that goes through three given points. However, if you loosen the problem constraints and only define the Y coordinate of the parabola’s top and allow its X coordinate …
3
votes
Integration error in high velocity
Say the object is 10 meters above ground. Assume that our dt (delta t) is 1 second. The object goes to the height of 9 meters at the end of the first iteration
Here lies your problem. It is true …
20
votes
Accepted
Sorting array of points in clockwise order
Your question is not precise enough. An array of points is only « clockwise » or « anti-clockwise » relative to a reference point. Otherwise, any array of three points can always be either CW or CCW. …
2
votes
Accepted
Math to set tangential force?
You need a unit vector tangent to the planet surface:
v = normalize((pY - oY, oX - pX))
Then just multiply v by your force amount.
1
vote
Find your value between four values in a grid based on distance, Unity
You do not need to do anything special: Perlin noise is a gradient noise and is designed to give you an interpolated value at any point, not just at the square corners. Just use your Perlin noise gene …
1
vote
Accepted
How does this point2LineDist() method works?
The direction vector of the red line is (CosTable[a], SinTable[a]). It is a unit vector.
Now consider the green line on your drawing. The vector along this line pointing towards (x, y) is orthogonal …
2
votes
Accepted
Why does Mathf.Log(x) return infinity in this case?
Here is a more numerically stable (for large values) way of getting Log(Fn) where Fn is the nth Fibonacci number. Let φ = (1 + sqrt(5)) / 2 and ψ = (1 - sqrt(5)) / 2. Then the nth Fibonacci number is: …
0
votes
calculating the weights for direction vectors to a target
The distance between the centre of the circle (x1,y1) and the target (x2,y2) is:
D = sqrt((x1-x2)² + (y1-y2)²)
So the distance between the target and any point on the circle varies between D - r an …
0
votes
Velocity Relative To A Vector
The “velocity in a space” can be broken down in two vectors, one that is the same direction as a, and one that is perpendicular to a.
The first vector has direction u and size su, computed as follows …
6
votes
Accepted
understanding spatial hash function behaviour and Knuth for int64
First of all, for uniformly distributed data, Knuth’s function i * 2654435761 >> 16 is definitely better than i * 2654435761 >> 8 because it shuffles more bits. An explanation follows.
Consider the m …
3
votes
How to calculate normal vector of a Bézier curve?
If vector (x,y) is a tangent vector of your curve, then the normal vector is simply (y,-x). So you just need to find a tangent vector, and it all depends on how exactly you define the curve.
If your …
3
votes
Usage of math.Atan2 in a 3D coordinate system with Unity
Beware of the argument order here. Here is what atan2 will give you:
atan2(x,z) is the angle between the (x,0,z) vector and the +Z axis in the Z-X plane.
atan2(z,x) is the angle between the (x,0,z) …
2
votes
Quaternion Slerp and Lerp implementation (with overshoot)
Here’s a little example. Suppose you slerp q0 and q1 with a value of t = 0.2 and a value of t = 0.4. This gives you a quaternion s(0.2) and a quaternion s(0.4). Quaternion multiplication also gives us …
1
vote
Accepted
Affine transformation: rotate a plane parallel to another plane
I need a way of translating a set of points P
I suppose you mean rotating here?
Let Z = (0,0,1). If cross(N,Z) has length 0, it means that all your points already lie in the desired plane. Other …
15
votes
Accepted
How do I lerp between values that loop (such as hue or rotation)?
It’s not always the best method, and it can be more computationally expensive (though this ultimately depends on how you store your data), but I will make the argument that lerping 2D values works rea …