A technique for using rays to determine points of intersection. Often used in lighting simulation.

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14
votes
4answers
7k views

Cast ray to select block in voxel game

I am developing a game with a Minecraft-like terrain made out of blocks. Since basic rendering and chunk loading is done now, I want to implement block selecting. Therefore I need to find out what ...
9
votes
3answers
6k views

How do I implement occluded lighting in a block-based 2D game?

I want to have 2D lighting that can be blocked by in-game objects. My game has a top-down view and all game objects are described by rectangles. Let's say I have a 10x10 world and I place a light at ...
15
votes
2answers
8k views

How can I implement lighting in a voxel engine?

I am creating the MC like terrain engine, and I have thought that lighting would make it look a whole lot nicer.The problem is that the blocks are not being lit properly when a block which emits light ...
3
votes
1answer
7k views

3D Ray Casting / Picking

I am not sure if I should post this link, but I feel this falls into game development just as much as it does math. I have a ray cast's far and near values and I am trying to calculate the end point ...
3
votes
4answers
247 views

Ray Triangle Intersection issue

I'm trying to perform ray triangle intersection on a mesh made of triangles. The below code seems to work fine but only about 50% of the time. The ray often gets into positions where no intersection ...
1
vote
1answer
168 views

Raycast Flashing problem

Can anyone tell me what is wrong with me code? If you can see, whenever the player is in range of the raycast, the enemy turns red. But for some reason, even when the player has meet the requirement ...
1
vote
1answer
5k views

OpenGL ES 2.0 gluUnProject

I've spent more time than I should trying to get my ray picking program working. I'm pretty convinced my math is solid with respect to line plane intersection, but I believe the problem lies with the ...
6
votes
1answer
4k views

More efficient way to implement Line of sight on a 2d grid with ray casting?

Consider a 2d grid of tiles, and an approximated sphere of coordinates - centered on the player - that represents line of sight. The goal is to block the line of sight beyond obstacles (ie walls). ...
1
vote
2answers
99 views

Cursor position to a 3D ray using angles

I've been stuck for a month trying to get gluUnProject working. After my attempts to use gluUnProject failed (as well as attempts to implement gluUnProject functionality manually) I implemented method ...
0
votes
1answer
3k views

Platformer raycast collision detection

I'm using Unity to create a 2D platformer. For collision detection, I'm using raycasting to detect any possible collisions with specific collision layers, and adjusting the desired delta x & y ...
4
votes
3answers
3k views

Why do we use physics engines for collision testing or raycasting?

There is a thing I don't understand about game engines: why it is so common to use physics engines to do raycasting or collision testing? Say that you have a 3D scene loaded in your scene manager ...
1
vote
1answer
69 views

Pixel Picking vs Raycasting

I was recently introduced to a way of picking in OpenGL known as pixel picking (or color picking). From my understanding, how this is done is that the scene is rendered to the back buffer with a ...
1
vote
1answer
155 views

How would I check the range against the entirety of an enemy object, and not just it's transform.position?

I want to be able to do range checks against the entirety of an enemy object, and not just it's transform.position. The enemy object can have it's side or nose within range, but range detection will ...
1
vote
0answers
603 views

How to identify whether the boundingvolume intersects with walls or floor when it doesnt return normals?

My game in jMonkey is the kind that use will have to place objects in a scene (which consist of walls and slabs and floor). All my models are centered at origin. When the user click a point I use ray ...
1
vote
2answers
687 views

Displaying sprites in a 2.5D raycasting engine

I'm developing a raycasting engine like the one used in DOOM, Wolfenstein 3D, etc. My engine is capable of correctly displaying walls and textures on walls, but I'm stuck at sprites rendering. Given ...
0
votes
1answer
33 views

How to refer to a object that has just been hit by a ray cast?

I would like to use RigidbodyConstraints.FreezeRotation;in order to freeze the rotation of an object that is picked up. The problem is I don't know how to refer (or call) the currently selected ...
0
votes
1answer
118 views

Getting ray using gluUnProject or inverted MVP matrix

I've read a lot of topics here, on SO, opengl.org etc. Example how gluUnProject should work (from NeHe tutorial): winX = (float)x; winY = (float)viewport[3] - (float)y; glReadPixels( x, int(winY), 1, ...
0
votes
1answer
401 views

Bounding Box in Monogame for mouse picking - Ray perspective

My mouse ray is screwing up precision. I don't really know how to fix it, maybe you guys can help. problem : (5.6mg gif) https://www.dropbox.com/s/v0z67afso88hsd1/perspective_ray.gif how i create ...
-1
votes
1answer
305 views

2D bouncing formula doesn't work properly

am new to unity, and i am trying to create a bouncing ball, so i've did many researches about bouncing realted physics and i found a formula : Formula: -2*(V dot N)*N + V Where V is the velocity ...