# Tagged Questions

95 views

### How do I find the angle between two 3D angles represented in this form?

I have two 3D angles, represented by [a1,a2] [a1,a2] where the a2 is < 180. My coordinates are represented as [X,Y,Z], where X,Y,Z are 64 bit ints (longs in my lang). My direction angles are ...
137 views

### Self colliding cloth physics

I've previously simulated cloth using Verlet integration but couldn't successfully get the cloth to collide with itself in an efficient way. The reason being is because I used a brute force algorithm ...
87 views

### Is an extra collision-mesh for level-data worth the hassle?

What is the optimal approach for collision-detection with the environment in an 3D engine (with triangle mesh based geometry, no bsp)? A) Use the render mesh [+] no need for additional work for ...
526 views

### Triangle-triangle continuous collision detection

I am making a 3D game engine and I use continuous collision detection. I am using Sphere-Trees to cull primitive collision checks to a minimum. However, I'd like to perform continuous ...
236 views

### XNA 3D Unable to Position Bounding Sphere

I have a collision method which seems like it would work, and it does, but the bounding sphere is always at 0, 0, 0. How do I fix this? Any more code and or details are avaliable upon request. Any ...
138 views

### Creating a collision shape for a complex model

I'm currently creating the collision system for my 3D XNA game. To check collisions with models (especially complex ones) like trees or other plants, I thought about rendering a low poly version of ...
53 views

### 3D Box Collision Data Import

I'm trying to implement a collision system using oriented bounding boxes, using a center for the box, it's extents as a 3D Vector and a rotation matrix, which is all stuff I picked up online and seem ...
66 views

### Collision detection - relative distance

Assume an object move toward a polygon board in 3D field . In order to detect whether the object collide in the board , according to the lecture notes of my Computer Graphics Course lecturer - it ...
784 views

### Moving bounding box in 3D using Libgdx

How do i go about moving a bounding box in libgdx? I want to make the bounding box capture my character and move with him. So ideally i want to be able to copy my vector 3 from my model instance and ...
196 views

### Collision Issues

When I run the collision code, there are no errors, but when I shoot the enemy nothing happens..... Any problems that are blindingly obvious? Class Level Variables public Model model { get; ...
242 views

### 3d Wall sliding collision

I'm working on collision for walls in my game and the way I currently have it I get stuck walking into a wall. I'm trying to make my character slide on the walls but still collide. My character moves ...
648 views

### How to check for cube collisions?

I want a method, which takes two "ObjectBox" objects (A "ObjectBox" has .getX() .getY() .getZ() .getSizeX() .getSizeY() .getSizeZ() methods) as a parameter and return true if the two Boxes are ...
215 views

### Collision detection in games in 3D - edge to edge cross product

I am having trouble understanding why, in a game collision detection, separating axis determination requires checking for the cross product of edges of the two polytopes as additional potential ...
650 views

### How do collision meshes work in games like Zelda on the N64?

I was recently reading about the technology of Ocarina of Time/Majoras Mask and discovered that world collision is done using a single triangle mesh (vertices, normals, etc) for an entire area. There ...
207 views

### How can I implement collision for a “pseudo-3D” game?

I'm looking for high level implementation details, not specifics. I've worked with bounding boxes before in some 2D games, but I'm currently tackling a "2D + depth" (2.5D?) style game along the lines ...
971 views

### How to do collision detection in 3D using bounding boxes?

I am using c++ in visual studio 2010 with opengl. I am trying to make a programme that has 2 boxes that are able to be stacked on top of each other but I am having some trouble with the collision ...
4k views

### Unity: OnCollisionEnter not called

I created a sphere object, added a rigidbody component (no kinematics) and attached a script to it like this: function Update () { } function OnCollisionEnter(collision : Collision) { ...
701 views

### AABB-AABB sliding collision response

I have many objects with AABBs and a player surrounded in an AABB. If I represent my player with a point everything works smooth with detection and wall sliding as a response (for example what wall ...
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### Help me debug my 3-d collision code [closed]

I have been havaing a problem doing 3-d collision in a game i have been trying to make for several weeks now. What i am trying to do is prevent a PlayerModel object from colliding with Obstacle(cube) ...
3k views

### Collision detection - Smooth wall sliding, no bounce effect

I'm working on a basic collision detection system that provides point - OBB collision detection. I have around 200 cubes in my environment and I check (for now) each of them in turn and see if it ...
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### 3D Collision Detection with XNA

So I'm trying to implement some collision detection in XNA. I'm aware of the Bounding Spheres, but I worry with the accuracy, most items in my game are cubic in nature, so it seems very square-peg in ...
305 views

### Collisions and camera tilt in XNA C# 3D Game [closed]

I am working on a game programming class project and need some help. I cannot find a good tutorial on how to get these 3 frictionless spheres to collide with each-other, the surface and the walls of ...
522 views

### 3d Collision Handling

I have trouble while detecting collisions on my 3D-Game. I have set-up Rays, to detect collisions (Screenshot) and my main-rountine already analyzes them. But now there's the question what to do ...
506 views

### Boat passing under a bridge in a 2D tile based RTS

I'm writing a 2D tile based RTS. And I want to add a 'pseudo 3D' feature to it - bridges over the rivers. I havent't start any coding yet, just trying to think how it fits the collision detection ...
217 views

### Normalizing the direction to check if able to move

i have a a room with 4 walls along the x and z axis respectively. My player who is in first person (therefore the camera) should have collision detection with these walls. I'm relatively new to this ...
521 views

### What is the best way to implement collision detection using Bullet physics engine and a track generated from a curve?

I am developing a small racing gam, the track is generated from a curve. As said above, the track is generated, but not infinite. The track of one level could fit with no problem in memory and will ...
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### Viewport.Unproject - Checking if a model intersects a large sprite

Let's say I have a sprite, drawn like this: spriteBatch.Draw(levelCannons[i].texture, levelCannons[i].position, null, alpha, levelCannons[i].rotation, Vector2.Zero, scale, SpriteEffects.None, 0); ...
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### How do I perform collision tests between two 3D oriented bounding boxes?

I want to test two 3D oriented bounding box objects against each other and stop them if there is a hit detected. How can I accomplish this using only the collision detection functions in the Bullet ...
2k views

### collision resolve sphere-aabb and aabb-aabb

I am currently working on a basic physics engine which does not consider rotations. At the moment I work on collision resolving between aabbs and spheres. Unfortunately I have no idea what a collision ...
854 views

### Efficient physics and collision detection for RTS

I'm thinking about writing my own RTS game and while I'm more or less clear about how the game engine should work, I need some directions as to how to implement physics and collision detection. Now, ...
1k views

### Checking for collisions on a 3D heightmap

I have a 3D heightmap drawn using OpenGL (which isn't important). It's represented by a 2D array of height data. To draw this I go through the array using each point as a vertex. Three vertices are ...
211 views

### Better way to go up/down slope based on yaw?

Alright, so I got a bit of movement code and I'm thinking I'm going to need to manually input when to go up/down a slope. All I got to work with is the slope's normal, and vector, and My current and ...
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The following code does not load the matrix correctly from jbullet. //box is a RigidBody Transform trans = new Transform(); trans = box.getMotionState().getWorldTransform(trans); float[] matrix = new ...
725 views

### OpenGL : Suggestion on handling collision detection and vertex data?

I was thinking how to do collision detection in my OpenGL application and came to conclusion that I should keep two copies of my geometry data. 1)First copy : Only for OpenGL rendering purposes.This ...
396 views

### Collision, then what?

I know how to check collision for example 2 spheres. But my question is how do I use the collsion response in a good way? How do I make my character unable to walk in to the Sphere? I've got to the ...
480 views

### 3D: How how handle like 500 NPC

I'm currently working on a 3D game. My game have like 10 NPC's and a really small world. But if I want to have a larger world with lots of NPC's? I think it's not a good idea to update and check ...
722 views

### What has the most efficient intersection test against an AABB tree - OBB, Cylinder or Capsule?

I'm currently trying to find collisions in 3D between a tighter volume than an AABB and a tree of AABB volumes. I just need to know whether they are intersecting, no closest distance or collision ...
1k views

### In very simple 3d racing games, how are collisions handled?

I was wondering how collisions in some simple 3d car racing games are done (especially in games like Outrun 2/Motoracer). In classic car racing games with complex environment (open world), I guess ...
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### Collision detection in 3D space

I've got to write, what can be summed up as, a compelte 3D game from scratch this semester. Up untill now i have only programmed 2D games in my spare time, the transition doesn't seem tough, the ...
2k views

### 3d bounding Box border xna

So, I'm trying to develop a 3d table tennis game, and I'm having problems when it comes to colliding the ball with the table. I have a bounding sphere for the ball and bounding box for the table, but ...
2k views

### How do I calculate collision response between a sphere and a plane?

I'm trying to create a simple 3D game and need to constrain the player within the limits of the game world. When the player hits the sides of the world I want the player's ship to bounce off slightly. ...
413 views

### 3d collision detection on non flat surface

i am developing a game which needs an accurate collision detection algorithm, when a object travels down a slope which isn't flat. To be more precise i need to simulate a skier who travels down a ...
829 views

### Inaccurate 3D model collision using XNA

I am creating a classic game in 3D that deals with asteriods and you have to shoot them and avoid being hit from them. I can generate the asteroids just fine and the ship can shoot bullets just fine. ...
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### 3d Collision detection help xna?

I was hoping if you could help me out here. I'm developing a 3d table tennis game, and got the collision detection working perfectly when the ball hits the racket. However, now I would like the ball ...
922 views

### XNA: Perform Collision Detection Against 3D Scene Geometry

How would one perform collision detection between a simple scene like the one below and a simple object like a sphere? I assume the best solution would involve convex hulls in some way but I have no ...
575 views

### XNA Automatic Collision detection from model?

This is going to be a rather vague question xD In XNA is there a way of working out if a point or rectangle is colliding with a 3D .x object? It is a big model, and would take a long time to map out ...
276 views

### detecting the coordinates where a bullet hits a mesh

I have a lot of complex objects in a scene and I'm looking for an efficient way to find which object a fired bullet hits, and to find the hit coordinates. It would be best if there was a lightweight ...
1k views

### Android collision detection of a 3d object based on a 2d projection

I am writing a game for android. We have an orthographic view setup, but the characters (ships, projectiles, etc). The enemies / characters will be able to rotate about the x axis. The problem is that ...