collision-detection

I'm currently working on a 2D shoot them up type of game, and I'm using a quad tree for my collision detections. I wrote a working quad tree that correctly pushes my actors into the nodes/leaves they belong to in the tree. However, I've got a few problems. Firstly, how do I actually use my quadtree to select against which other objects an object should test collisions ? I'm unsure about how this is done. Which brings up a second question. Say I have an object in node that is not a neighbour of another node, but that the object is large enough that it spans a few node, how can I check for an

Given 2 set of points ((x1,y1,z1),(x2,y2,z2),(x3,y3,z3)) and ((p1,q1,r1),(p2,q2,r2),(p3,q3,r3)) each forming a triangle in 3D space. How will you find out whether these triangles intersect or not? One obvious solution to this problem is to find the equation of the plane formed by each triangle. If the planes are parallel, then they don't intersect. Else, find out the equation of line formed by the intersection of these planes using the normal vectors of these planes. Now, if this line lies in both of the triangular regions, then these two triangles intersect, otherwise not. trianglesIntersect

I am pretty new to both CANVAS and Kineticjs but I feel what I am attemping should be much easier then I am making it out to be. Basically this is what I have so far: The code I am attempting to use is from kineticjs Stop drag to a shape when overlaps with another solution but was unable to get it to work. Please check the live jsfiddle code var isRectCollide = function(target, box) { if (target.x - target.width >= box.x + box.width && target.y - target.height >= box.y + box.height && target.x + target.width <= box.x + box.width && target.x + target.height <= box.y - box.height ) return false;

Alright so I've been trying for quite some time too Raycast in libgdx for 3d collision detection based on where im looking.. But I've drawn a blank and doesn't seem to be any documentation anywhere. Would someone be kind enough to send me in the right direction? It is actually really easy with libgdx to achieve what you are trying to do. The following is what I'm using to do a ray test and find the closest collision object that my ray would hit. Let's assume it is located in a class called BulletUtil . private static final Vector3 rayFrom = new Vector3(); private static final Vector3 rayTo =

I've been working on a physics simulation with circles in Qt. Thus far the easiest way to define circles I found is to make a QRect object and then draw the ellipse with that rectangle as a "blueprint". Now I've just got the problem that it paints a circle but the hit box for the hit detection is still a square, which looks rather awkward. I've not been able to find a solution for it thus far and hope to find some help here. QRectF Ball::boundingRect() const { return QRect(0,0,20,20); } void Ball::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) { QRectF rec =