removed old collision code, added this to README

README.md

@@ -10,7 +10,6 @@ groverburger's 3D engine (g3d) simplifies [LÖVE](http://love2d.org)'s 3d capabi
 - .obj file loading
 - Basic first person movement and camera controls
 - Perspective and orthographic projections
-- Functions for simple collision handling
 - Simple, commented, and organized
 
 ## Installation
@@ -60,3 +59,9 @@ end
 - Use basic first person movement with `FirstPersonCameraMovement(dt)` and `FirstPersonCameraLook(dx,dy)`
 
 For more information, check out the `model.lua` and `camera.lua` files.
+
+## Collision Detection
+
+Please use the [CPML](https://github.com/excessive/cpml) library or refer to [3DreamEngine](https://github.com/3dreamengine/3DreamEngine) for their 3D collision code.
+Mozilla also has a [nice article](https://developer.mozilla.org/en-US/docs/Games/Techniques/3D_collision_detection) on basic 3D collision detection.
+g3d no longer offers collision detection, instead focusing only on making 3D rendering as simple as possible.

g3d/matrices.lua

@@ -62,6 +62,7 @@ function GetProjectionMatrix(fov, near, far, aspectRatio)
     local bottom = -1*top
     local right = top * aspectRatio
     local left = -1*right
+
     return {
         2*near/(right-left), 0, (right+left)/(right-left), 0,
         0, 2*near/(top-bottom), (top+bottom)/(top-bottom), 0,
@@ -79,6 +80,7 @@ function GetOrthoMatrix(fov, size, near, far, aspectRatio)
     local bottom = -1*top
     local right = top * aspectRatio
     local left = -1*right
+
     return {
         2/(right-left), 0, 0, -1*(right+left)/(right-left),
         0, 2/(top-bottom), 0, -1*(top+bottom)/(top-bottom),
@@ -175,62 +177,3 @@ function TransposeMatrix(m)
         GetMatrixXY(m, 4,1), GetMatrixXY(m, 4,2), GetMatrixXY(m, 4,3), GetMatrixXY(m, 4,4),
     }
 end
-
-----------------------------------------------------------------------------------------------------
--- detect collisions between a model and a vector
-----------------------------------------------------------------------------------------------------
--- these functions are used for the Model:vectorIntersection function
-
-local function subtractVector(v1,v2,v3, v4,v5,v6)
-    return v1-v4, v2-v5, v3-v6
-end
-local function crossProd(a1,a2,a3, b1,b2,b3)
-    return a2*b3 - a3*b2, a3*b1 - a1*b3, a1*b2 - a2*b1
-end
-local function dotProd(a1,a2,a3, b1,b2,b3)
-    return a1*b1 + a2*b2 + a3*b3
-end
-local DBL_EPSILON = 2.2204460492503131e-16
-
--- taken and modified for efficiency from Cirno's Perfect Math Library
--- using just numbers and not vector tables for efficiency
-function FastRayTriangle(p1,p2,p3, d1,d2,d3, t11,t12,t13,t21,t22,t23,t31,t32,t33)
-    local e11,e12,e13 = subtractVector(t21,t22,t23, t11,t12,t13)
-    local e21,e22,e23 = subtractVector(t31,t32,t33, t11,t12,t13)
-    local h1,h2,h3 = crossProd(d1,d2,d3, e21,e22,e23)
-    local a = dotProd(h1,h2,h3, e11,e12,e13)
-
-    -- if a is too close to 0, ray does not intersect triangle
-    if math.abs(a) <= DBL_EPSILON then
-        return false
-    end
-
-    local f = 1 / a
-    local s1,s2,s3 = subtractVector(p1,p2,p3, t11,t12,t13)
-    local u = dotProd(s1,s2,s3, h1,h2,h3) * f
-
-    -- ray does not intersect triangle
-    if u < 0 or u > 1 then
-        return false
-    end
-
-    local q1,q2,q3 = crossProd(s1,s2,s3, e11,e12,e13)
-    local v = dotProd(d1,d2,d3, q1,q2,q3) * f
-
-    -- ray does not intersect triangle
-    if v < 0 or u + v > 1 then
-        return false
-    end
-
-    -- at this stage we can compute t to find out where
-    -- the intersection point is on the line
-    local t = dotProd(q1,q2,q3, e21,e22,e23) * f
-
-    -- return position of intersection and distance from ray origin
-    if t >= DBL_EPSILON then
-        return t, p1 + d1*t,p2 + d2*t,p3 + d3*t
-    end
-
-    -- ray does not intersect triangle
-    return false
-end

g3d/model.lua

@@ -107,45 +107,3 @@ function Model:draw()
     love.graphics.draw(self.mesh)
     love.graphics.setShader()
 end
-
-local function dotProd(a1,a2,a3, b1,b2,b3)
-    return a1*b1 + a2*b2 + a3*b3
-end
-
--- check if a vector has collided with this model
--- takes two 3d vectors as arguments, sourcePoint and directionVector
--- returns length of vector from sourcePoint to collisionPoint
--- and returns the collisionPoint
--- length will be nil if no collision was found
--- this function is useful for building game physics
-function Model:vectorIntersection(sourcePoint, directionVector)
-    local length = nil
-    local where = {}
-
-    for v=1, #self.verts, 3 do
-        if dotProd(self.verts[v][6],self.verts[v][7],self.verts[v][8], directionVector[1],directionVector[2],directionVector[3]) < 0 then
-
-            local this, w1,w2,w3 = FastRayTriangle(sourcePoint[1],sourcePoint[2],sourcePoint[3],
-                directionVector[1],directionVector[2],directionVector[3],
-                self.verts[v][1] + self.translation[1],
-                self.verts[v][2] + self.translation[2],
-                self.verts[v][3] + self.translation[3],
-                self.verts[v+1][1] + self.translation[1],
-                self.verts[v+1][2] + self.translation[2],
-                self.verts[v+1][3] + self.translation[3],
-                self.verts[v+2][1] + self.translation[1],
-                self.verts[v+2][2] + self.translation[2],
-                self.verts[v+2][3] + self.translation[3]
-            )
-
-            if this then
-                if not length or length > this then
-                    length = this
-                    where = {w1,w2,w3}
-                end
-            end
-        end
-    end
-
-    return length, where
-end