A branch of mathematics concerned with questions of shape, size, relative position of figures, and the properties of space.
5
votes
0answers
45 views
Dual Contouring - Finding the feature point, normals off
I am following this tutorial to implement Dual Contouring
http://www.sandboxie.com/misc/isosurf/isosurfaces.html
My data source is a grid 16x16x16;
I traverse this grid bottom to top, left to right, ...
2
votes
1answer
34 views
Finding vector from a vertex to a plane
I am trying to implement Dual Contouring, following serveral sources, mainly http://www.sandboxie.com/misc/isosurf/isosurfaces.html
but now I want to implement finding the feature point as explained ...
5
votes
4answers
186 views
Creating force shields: the most efficient way of deforming/reshaping a simpler convex mesh so it envelopes a complex mesh?
So, the best way I can think of how to explain what I need is the following (images used here are just random images found trough google image search).
What I am trying to create during run-time is ...
5
votes
1answer
102 views
Finding new position after collision with multiple colliders
What is the most accurate way to find the correct position to where a moving character should be re-positioned as a collision-resolution, after it has collided with multiple colliders?
The figure ...
5
votes
2answers
76 views
How to find out the vertices of the polyhedron formed by the overlapping area of two rotated boxes?
What is the most efficient way for finding out the vertices of the polyhedron formed by the overlapping area of two rotated 3D boxes?
If it is still confusing what I mean by "polyhedron formed ...
7
votes
4answers
446 views
How do I efficiently check if a point is inside a rotated rectangle?
Part for the sake of optimization, part for learning purposes, I will dare to ask: How can I most efficiently check whether a 2D point P is inside a 2D rotated rectangle XYZW, using C# or C++?
...
5
votes
2answers
731 views
Is there an efficient way to identify in which run-time generated room a character is, in a non-grid 3D environment? How?
Here is what I am trying to implement. I wrote a script that allows the player to place walls during run-time, in non grid-based 3D environment (walls can be diagonal with rotation ...
1
vote
0answers
75 views
Most efficient way to calculate angle between two line-segments that do not necessarily touch each other
Although I found answers on calculating angles from vectors, I didn't find a specific way to calculate angles between line-segments that do not necessarily touch each other (I say "not necessarily ...
2
votes
1answer
44 views
Realistic angular velocity for rolling sphere in Unity 5.1
I'm trying to make a small 2D game with a rolling ball/sphere using Unity 5.1, but if find the angular velocity of the ball weird.
On this first image (http://imgur.com/8wBoGms), you can see the ...
2
votes
2answers
93 views
Most efficient way to get the world position of the 8 vertexes of a Box Collider (C#)
What I am looking for is the most efficient way to get the world position of the 8 vertexes of the Box Collider of a freely rotated Gameobject. I cannot use collider.bounds since object is rotated, ...
1
vote
0answers
38 views
Detecting the two Vector3 that determine the bottom-edge of the side of a box-collider that had collision (with C#)
So, I understand that plenty of questions have been posted on how to detect which side of a Box Collider had collision. However, what I am trying to achieve is a little different.
I want to find out, ...
1
vote
0answers
28 views
Calculating Minimum Translation Vector in Separating Axis Theorem based algorithm
In the 2D SAT collision determination algorithm, you project the convex polygons onto each potential separating axis. Supposing the polygons intersect, from what I understand, the axis for which the ...
0
votes
2answers
63 views
Optimal way to find point D that lays at the perpendicular line between point A and line BC
I am trying to write a script in C# to find the position of point D in 2D space in a specific scenario.
I know the (X,Y) position of point A, which never happens to be on the line that contains the ...
1
vote
3answers
107 views
What's the most efficient way to find the position of a point in relation to corners of a rectangle despite rectangle's scale
I am struggling to achieve the following with C# (in Unity). I need to find the position of the points that lay at a given distance (let's say 1m) from the corners of a rectangle, in a way that the ...
4
votes
2answers
66 views
How to properly rotate towards a local point in Unity C#? (a local LookAt)
I am having a nightmare trying to make a child object rotate towards a given point of its parent object, similar to what is possible at the world level when using LookAt.
The problem is that most ...
1
vote
0answers
45 views
Rotate perspective camera to align screen width to procedural object's width (Unity, C#)
I give up. After much trying and searching, I have to say I was unable to achieve the following task, for which I must call for your wise advice.
In my current Unity 5 application (using C#), there ...
0
votes
0answers
20 views
Drawing shapes within a rectangle area
I am working on a Objective-c project where I need to draw multiple rectangle shapes inside a rectangle area like the attached image. Basically calculating CGPoints inside the CGRect.
Thanks in ...
0
votes
1answer
40 views
Project 2d click/touch onto 3d plane
I have a 3d scene that contains an infinite plane that is NOT parallel to the camera (so every screen coordinate corresponds to a point on this plane- in other words, there are no possible invalid ...
9
votes
4answers
210 views
How do I interpolate around a rectangle?
I want to make a fancy animation where a point travels around a rectangle. I want to find the point's position at a time t.
The rectangle is given by X, Y, Width and Height.
Is there an algorithm ...
1
vote
1answer
85 views
Sliding DOOM style collision resolution against arbitrary 2D geometry
I've been working on a HTML5 canvas raycasting engine for the web browser, with the end goal of making a simple FPS game in the style of the early 90s. The engine sits somewhere between Wolfenstein 3D ...
0
votes
0answers
23 views
boost/geometry replacement in Java/for the JVM (Destructable Box2D terrain)
I'd like to reimplement https://github.com/seemk/DestructibleBox2D in Java. The main problem is finding an adequate replacement for the boost/geometry library.
Any ideas?
0
votes
0answers
34 views
3D Picking: Doesn't Work Consistently
I'm trying to implement a 3D picking function that at the moment simply calculates the ray being sent from the camera after the user clicks the mouse on the window.
It kind of works well when the ...
0
votes
2answers
104 views
Rotate coordinates back after rotating game context (geometry)
To achieve something similar to the image below using HTML5 canvas one can simply write the following:
var TO_RADIANS = 0.0174532925;
context.translate(30, 20);
context.rotate(30 * TO_RADIANS);
...
0
votes
0answers
24 views
Making a node map with PNG alpha channels
I currently creating a 2d game that requires the usage of boats that travel from one country to another. The countries are individual objects with there own png. Nehow I've got the original map of the ...
2
votes
2answers
59 views
Detect collision that happen between frames, between slices of moving, rotating circles?
To detect a collision between two circles, we check if the distance between their centers is smaller than the sum of their radii.
To detect a collision between a slice (in this case half) of a circle ...
-1
votes
1answer
67 views
Why is this unity camera moving in weird directions?
I have the following script
public class CameraScript : MonoBehaviour {
public bool AllowZoom;
public float zoom;
public float Speed;
Transform board;
void Start(){
...
3
votes
1answer
245 views
How can I mask this CanvasRenderer?
I'm creating a text box that allows for selectable text, based off of Unity's InputField. An issue I am now facing is that the selection highlight does not respond to masks (The parent has a mask, but ...
0
votes
2answers
56 views
Calculate land center on grid
I have a grid based game. The main map is 2d array with land ids, something like this (here are 2 lands on the map, one formed where the 1's are and one formed by where the 2's are):
[ 1 , 2 , 2 ]
[ ...
0
votes
0answers
155 views
Taking a 2D slice of a 3D volume
I have a regular 3D polygon and I'd like to display 2D slices of it.
What is the best way to achieve this? (Preferrably in OpenGL, but a general algorithm/tecnique would be good as well).
I've ...
0
votes
1answer
80 views
Is there a way of moving the transform of an object relative to it's geometry
I have a number of objects (mostly prefabs) that have their transform origin in inconvienient places such as about 1 unit to the left of the actual geometry or somewhere inside an object where it's ...
1
vote
1answer
67 views
Ortho projection of 3D points with a vector
I have 3D points and I need to make an 2D orthographic projection of them onto a plane that is defined by the origin and a normal n. The meaning of this is basically looking at the points from the top ...
4
votes
1answer
109 views
Suboptimal A* Pathfinding Solution Example using Manhattan Distance Heuristic
I believe using an overestimating heuristic with A* is not guaranteed to find the shortest path. Assuming an agent can travel as a bird using euclidean distances, the manhattan distance provides just ...
35
votes
9answers
6k views
How can I quantify a drawn line's straightness?
I'm working on a game which requires players to draw a line from a point A(x1,y1) to the other point B(x2,y2) on the screen of an Android device.
I want to find how well that drawing fits to a ...
0
votes
2answers
115 views
Outline of plane slice of arbitrary object
How would you extract the outline of a shape from slicing a plane through an arbitrary object?
Note: This is related to my Unity Answers question, but not exactly the same.
0
votes
1answer
225 views
Rotate Object Towards Direction in 2D
For my RTS game's physics engine, I'm trying to find out a clever way to make a unit face the direction it's moving in. Given a Vector2d direction of movement (its normalized velocity), how can I ...
1
vote
1answer
39 views
Maya 2015 Collada mesh transforms not applied
I am trying to load a dae (Collada) model into my 3d engine. The problem is they export the vertices and transforms seperately. So in Maya 2015 it looks like this
In the game engine I have it simply ...
2
votes
1answer
91 views
Mapping Coplanar Vertices in 3D space on to a 2D Plane
Say I have a plane specified by a normal vector and point on the plane.
I want to specify a 2-D co-ordinate system that lies 'across' the plane, and then use that to find the 2-dimensional distance ...
0
votes
2answers
166 views
Moving OBB vs. triangle intersection test
Requirements: to write a test function that, given a moving OBB (oriented bounding box) and a triangle, returns true whenever the OBB hits the triangle.
The OBB is described by its half extents (h1, ...
0
votes
0answers
33 views
Rotating between two coordinate frames
I have two coordinate frames, A and B. I want to create the rotation matrix RAB which takes you from A to B. A is a right-handed system, and B is a left-handed system. Furthermore, after moving from a ...
0
votes
1answer
139 views
Collision Detection algorithm using Line Detection
For a 2D physics sandbox I am working on, I need a way of detecting detecting a collision using lines. This sandbox uses a class called Particle, which has a x and a y (stored as a struct called ...
0
votes
1answer
67 views
How can i calculate that normal lays in same part of plane with point?
I.e. n0 for A and n1 for B. Plane divided by plane CD.
0
votes
0answers
57 views
Fat geometry shader
I've seen this video: all the geometry seems to grow and become fat. Nice effect.
I'm just approaching the shader matter, and I'm still have to learn a lot about how to change geometry via shaders. ...
0
votes
0answers
25 views
How does collision detection work? [duplicate]
I was curious on how hit collision works in games. I know there is a simple method that gives every object in a 2D or 3D world a recengular hitbox that makes it easy to detect a collision, but when ...
12
votes
6answers
2k views
What's the fastest way checking if two moving AABBs intersect?
I have two AABBs that are moving, what's the fastest way to check if they will intersect under a frame?
By moving I mean not just to check with the usual rectangle intersection method, I mean some ...
5
votes
5answers
4k views
How can I test whether points are within a polygon?
I have 2D-points, which boundaries depict a polygon. The points are at integer positions (no fractions possible).
Now I want to build an enumerator in C# that returns all points that are inside the ...
2
votes
3answers
705 views
How do I interpret the dot product of non-normalized vectors?
I know that if you take the dot-product of two normalized vectors, you get the cosine of the angle between them.
But if I take the dot-product of two non-normalized vectors (or one normalized, one ...
1
vote
0answers
77 views
How can I keep vertex order the same on every Instantiate()?
While trying to resolve another question, I have discovered that if I Instantiate() from a prefab, the order of the mesh vertices (and therefore triangles) is inconsistent between instances. This is ...
1
vote
1answer
55 views
Algorithm that cover one mesh by another mesh
Suppose I have two meshes (Let call me first MeshShirt and second - MeshBody)
Meshes are aligned (if i render both MeshShirt "covers" MeshBody). But some parts of the body are not "under" the ...
0
votes
1answer
183 views
Formula to measure uv-mapping distortion
Does anyone know a simple way of calculating (offline) the amount a texture is distorted when mapped to a triangle like the following?
Vertex Position UV Coordinates
A (Ax, Ay, Az) ...
1
vote
1answer
157 views
Chamfered cube geometry generator
I'm trying to create a geometry generator for a "Chamfered Cube". I've got the vertices working, but I'm stuck with creating the faces. I don't really know how I could re-arrange my algorithm to ...
