Questions tagged [trigonometry]
A branch of mathematics that studies triangles and the relationships between their sides and the angles between these sides.
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Why are rotations in 2D game engines often counter-clockwise = positive systems?
I was looking over the API for a game engine a friend was developing in her spare time. She made the decision to make positive angles rotate in a clockwise direction. This immediately struck me as odd....
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1answer
85 views
SIMD and Inverse Tangent
I'm calculating spherical UV coordinates in a loop, trying to get GCC to vectorize the code.
Here's a compile-able example of what it looks like.
...
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1answer
67 views
Triangular Metric
Given a point inside a unit equilateral triangle, how does one rotate it across the triangle perimeter? I.e. the triangle outline serving the same purpose as circle's circumference. That is actually a ...
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2answers
56 views
I need help with calculating the angle my character is aiming at
So im doing this program where i want my hero to shoot to the direction its facing , but for this job to get done i need to calculate the angle my hero is facing with Math.atan2() , atleasts thats ...
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38 views
Adding spread to velocity Vector3D
I am trying to give an object a velocity spread (e.g. shotgun bullets or particle effect).
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2answers
73 views
How to get the Javascript equivalent of GameMaker's `hspeed` and `vspeed` given only `direction` and `speed`?
I'm using a NodeJS server to control NPC movement in a multiplayer game, and when they get too close to the edge of the room I need to reverse either the horizontal or vertical components of their ...
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1answer
44 views
Sum of FoV enemies
so what I need is to calculate the sum of players' Field of view.
Put simple, In a 2d space, I want to check how much they cover (in degrees).
So here are a couple of use cases to explain by example:
...
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0answers
29 views
Camera LookAt position with fixed screen position
I have a perspective "lookAt-type" camera. I'm trying to compute specific focus point of the camera, which should be placed in the middle of the screen: I also have a custom 3d point in world space, ...
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1answer
51 views
Finding Closest of 8 Possible Angles to Theta Value
I'm working on creating a gesture recognition system, and I saw one simple implementation that isn't as accurate, but is really easy to implement. The idea is that you have a unit circle with the 8 ...
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2answers
84 views
How to panning camera on XZ axis with different angles
I have an Orthographic camera where the position is { x:0, y:100, z:0 } and is pointing/looking at { x:0, y:0, z:0 }. At this ...
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1answer
26 views
Why does the first red-zone sometimes appear too close to the border in my battle-royale red-zone feature?
The Problem:
If you've ever played or watched some gameplay of a battle royal game (like PUBG, for example), you'll always find an event during any battle called the red zone.
Basically, at a ...
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1answer
112 views
Combine rotation XZ (horizontal) with YZ (vertical). Math formula
I'm trying to make a rotation vertically and horizontally around a point at the same time but I'm not able to combine both.
I have this formula for the horizontal rotation:
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2answers
158 views
Algorithm to produce a 2D 'flying through space' effect like the old Windows screen saver
I am old. My high school maths is a long way in my past and I am struggling to devise an algorithm that will produce a 2D 'flying through space' effect like the old Windows screen saver. It has—
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1answer
28 views
Getting an object to move in another objects direction
I have a player and an enemy, both have x and y values, and I want to move the enemy to the player and have them 'touch' over time in a speed that I can determine, I tried calculating the angle ...
1
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1answer
209 views
Move object at angle like a sine wave
I currently have this code, which moves an object in a straight line at an angle, where "dir" is the angle.
velX = (float)(Math.cos(Math.toRadians(dir))) * speed;
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1answer
43 views
Aim/Scope Oscillation Algorithm
I have been struggling to find an algorithm to implement something that will make a direction oscillate within a cone constraint, in a helix-shaped fashion as in photo (it will always go back to the ...
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3answers
142 views
Are there recursive variants for trigonometric functions to potentially improve performance?
This is perhaps a better question for mathematics SE, however, this deals more with the performance side of gaming, and software in general. When I say recursive function, I mean recurrence relation.
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2answers
518 views
How can I correct an unwanted fisheye effect when drawing a scene with raycasting?
Hello I have a game using raycasting for the TI Nspire in Lua, and when the player faces a wall so that their degree they are facing is perpendicular to the length of the wall, I am having what is ...
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0answers
64 views
Calculate smooth transition between local space angles
I'm trying to calculate direction of moving character (to rotate it's animation).
I have something like this:
Character can have 4 cardinal directions. The rotation is calculated from the current ...
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1answer
42 views
Moving a point on a rotating sprite
I've been trying to get sprites to stay on a set point on another rotating sprite. At the moment, it's very inaccurate, the original position is wrong, and when the rotation is applied the sprite ...
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0answers
17 views
How to calculate Camera “correct” position and distance to Frame all my Scene? [duplicate]
Consider I have N dynamic points on my Scene, I would like to "frame" all them, with my Camera.
How can i calculate (at runtime) Vector3 Position to correctly frame all my scene ?
This is my idea:
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0answers
313 views
Help with simple 2D Lens Flare effect
I'm currently trying to do a Lens Flare effect in a 2D game (Unity 3D) and i'm having problems with element positioning.
This are my elements in hierarchy. "Camera Container" it's a GameObject, ...
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2answers
524 views
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1answer
84 views
Why is my sprite moving 90 degrees to the right?
I have a sprite which i'm trying to move towards the top of the screen with the left and right buttons adjusting the heading.
However when my heading = 0; my ...
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1answer
290 views
Getting the current 'Forward' direction Vector values into code and how to use them?
Im having some trouble visualising how the maths works for this particular problem. Back when i coded in 2d only this was often a stumbling point for mine even when only dealing with an x and y axis.
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2answers
357 views
Why doesn't games use CORDIC for sin and cos?
If the game devs add CORDIC sin cos calculation to their games, their games will have much better FPS. Why do they use normal sin cos function (e.g. Math.sin) instead of CORDIC?
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435 views
Unity Mathf.Atan2 algorithm complexity
using Unity5.5.1f;
using C#;
So I have a circle (2D) divided equally by 16 directions, and I also have a direction V which is different from the other 16.
In order to know which direction is the ...
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1answer
132 views
Translating yaw degrees into 2D movement
I've been hitting my head on the wall for a while with this, and I'm almost sure I'm overcomplicating it.
I have a variable for yaw in degrees (and also pitch and roll, but those should be irrelevant)...
3
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1answer
115 views
Math behind drawing one game object relative to another?
Let's say I have a square (a) and I want to draw another square (b) that stays on one corner of the square (a).
Square (a) can rotate and move around the game world, what math would be used to keep ...
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2answers
162 views
Dealing with vectors in multiple planes
Say I have my main "screen" plane, where vectors can be represented
I "know"/can represent vector Q, but the only information I know about vector R is relative to Vector Q. An easy way to visualize ...
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2answers
553 views
Find vector tangent to circle through a point
C2 and P1 are known points. Radius of circle C2 is also constant and known. I am trying to find point T to eventually construct line p1-t, which is tangent to circle c2.
I have made an attempt ...
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1answer
518 views
Mapping polar coordinates to cube
I am trying map polar coordinates to points on a cube. I was able to map the front, back, left and right faces of the cube, but I am struggling with the top and bottom. Here is what I have:
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1answer
1k views
LibGDX How can I draw a line at a specific angle
I'm working on a 2D platformer, shooter game and I'm attempting to draw a line to serve as a guide to indicate where the player is shooting. The line should be drawn from the player's sprite to the ...
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1answer
50 views
Coordinates of the corners of a rectangle bridging two circles
I am implementing a game that involves slingshots and circular objects. I have gotten the basic "geometric" construction down for rendering the slingshot, but I am having trouble implementing this in ...
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2answers
39 views
How to work out the height of a point on a tilted surface?
I have a plane which gets tilted on the X and Z axis (y+ is the normal).
Given an X and Z coordinate and the X and Z rotation of the plane, how do I find out the height (Y) at that point?
I assume ...
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1answer
7k views
Unity 3D - Rotate (smoothly) towards a target
I wanted to know if there is a method on which I can rotate an object with an angle given (a float to be precise), I use trigonometry to calculate the angle between the two objects in a (x, z) plane ...
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3answers
543 views
Calculate target angle to a certain Vector
I'm developing a 3D game in LWJGL.
I have a player class and a monster class and I need the monster class to chase the player when the player is within a certain distance.
For that I have the monster ...
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1answer
65 views
Rotating vector based on the position of another vector? [duplicate]
Sorry for terrible picture but lets say we have a unit vector A and we have vectors B and C. So for vector B I would want to rotate in a positive direction because the vector is "above A" and for ...
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1answer
27 views
Increasing mass in ineleastic collision by orders of magnitude resultsin little change in velocity
When increasing my rocketMass from 10 to 1000 or to a 1000 or bringing my shipMass down to 1, I notice very little increase in how far the ship's final inertia is. I'm expecting that increasing from ...
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1answer
160 views
Why don't Javascript Math.cos doesn't match this vector tutorial?
I'm following
http://www.mathguide.com/lessons2/Vectors.html#combining
...
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1answer
47 views
Turning x and y difference between two points into a projectile moving between them at a fixed speed
In a libgdx project of mine, I have two units on a 2d field who want to fire at each other. They both know the x and y distance to each other by subtracting their enemies position from their own:
<...
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2answers
81 views
Algorithm for spacing points out among a line
I'm writing an angled tile system, and my implementation is to have a starting height and an ending height inside the tile.
Like so:
The starting and ending height allow me to get the length of the ...
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0answers
62 views
Slide along Surface
I'm very bad at Math and trigonometric functions (And I dunno if this questions fits here)
I have a surface normal as a direction vector.I want my character slide along the surface, if the angle of ...
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1answer
123 views
Why does this whirlpool simulation not work?
I am trying to create a simple whirlpool simulation, where particles are constantly compelled to move towards a point in a whirlpool like fashion.
To do this I do the following (in sudo code)
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1answer
165 views
How to avoid 2d enemy using trigonometry?
I'm making a game in Javascript & HTML5.
I have a "bullet" (let's call it so) that needs to reach the enemy (at fixed position) and that need to avoid the enemy's "bullet".
To make the bullet ...
1
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1answer
99 views
Java- Trig based movement
I have been trying to create a smooth movement technique that would allow me to move in all directions, not just the 8 cardinal directions.
I have tried to use this doing trig, and while the ...
0
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1answer
86 views
How to rotate a triangle to look at a point?
Lets say I have a triangle defined by 3 vertices and a center point, how do I rotate the triangle so its normal is looking at a specified point?
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2answers
582 views
Guided Missile with Constant Time
I'm building a game with players and missiles.
I want to fire a missile from P1 to P2. The missile should always take exactly five seconds to reach P2. The missile should also track P2. If P2 moves ...
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1answer
40 views
How does this point2LineDist() method works?
I was browsing Wolf3D JS port and bump into that method :
...
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1answer
448 views
Require maths help calculating deflection angles of quadrants
For each quadrant, I need to find a neat way of calculating the deflection angle for a small circular object striking a circle, as shown in the diagram.
Angles a and b are already known.
Angle a is ...
