Fixed surface normal calculation bug.

[raymarcher.git] / raymarch.lua

diff --git a/raymarch.lua b/raymarch.lua
index f1dbc3c..5bace40 100644 (file)
--- a/raymarch.lua
+++ b/raymarch.lua
@@ -11,24 +11,26 @@ require "Textures"
 local T = Textures
 
 local eps = 0.01
-local max_dist = 50
-local bg_col = {1,0,1}
+local max_dist2 = 20^2
+local bg_col = {0.1,0.1,0.1}
 
 local function calculate_normal(sdf, l)
    local delta = 1e-3;
-   return -V.new{sdf(l+V.x*delta).dist-sdf(l-V.x*delta).dist,
-                 sdf(l+V.y*delta).dist-sdf(l-V.y*delta).dist,
-                 sdf(l+V.z*delta).dist-sdf(l-V.z*delta).dist}/(2*delta)
+   return V.new{sdf(l+V.x*delta).dist-sdf(l-V.x*delta).dist,
+                sdf(l+V.y*delta).dist-sdf(l-V.y*delta).dist,
+                sdf(l+V.z*delta).dist-sdf(l-V.z*delta).dist}/(2*delta)
 end
 
-local function march(location, ray_dir, sdf, count)
+local function march(start, location, ray_dir, sdf, count)
+   if V.norm2(location-start) > max_dist2 then
+      return bg_col
+   end
+   
    local p = sdf(location)
    if p.dist < eps then
       return p.texture(location, ray_dir, calculate_normal(sdf, location-(ray_dir*eps)), count)
-   elseif p.dist > max_dist then
-      return bg_col
    else
-      return march(location + ray_dir*p.dist,
+      return march(start, location + ray_dir*p.dist,
                    ray_dir, sdf, count+1)
    end
 end
@@ -44,6 +46,8 @@ local function render(scene, width, height, filename)
    local right = V.normalize(c.right)
    local up = V.cross(right,cam_dir)
    local aspect = height/width;
+
+   local normalize = V.normalize -- optimization
    
    for y=1,height do
 
@@ -51,11 +55,11 @@ local function render(scene, width, height, filename)
          print(y/math.floor(height/10) * 10 .. "%")
       end
 
-      local rayy = cam_dir + up*((y/height - 0.5)*c.fov*aspect)
+      local rayy = cam_dir + up*((0.5 - y/height)*c.fov*aspect)
 
       for x=1,width do
-         local ray_dir = V.normalize(rayy + right*((x/width - 0.5)*c.fov))
-         local col = march(c.location, ray_dir, scene.sdf, 0)
+         local ray_dir = normalize(rayy + right*((x/width - 0.5)*c.fov))
+         local col = march(c.location, c.location, ray_dir, scene.sdf, 0)
          col = {math.min(col[1]*255, 255),
                 math.min(col[2]*255, 255),
                 math.min(col[3]*255, 255)}
@@ -74,13 +78,14 @@ end
 
 
 local scene = {
-   sdf = O.union(P.make_sphere(V.new{0,0,0}, 1,
-                       -- T.make_count_texture()),
-                               T.make_phong({V.new{2,-1,2}}, {0,1,0},
-                                  1.0, 0.5, 100)),
-                 P.make_sphere(V.new{1.5,0,1.0}, 0.5,
-                               T.make_phong({V.new{2,-1,2}}, {0,0,1},
-                                  1.0, 0.5, 100))),
+   sdf =
+      O.union(
+         P.make_sphere(V.new{0,0,0}, 1,
+                       T.make_phong_texture({V.new{2,-3,1}},
+                          T.make_solid_pigment({0,1,0}),
+                          0.2, 0.7, 1.0, 100)),
+         P.make_plane(V.new{0,0,-3.0}, V.new{0,0,1},
+                      T.make_flat_texture(T.make_checkered_pigment({0,0,1}, {1,1,1})))),
                                
    camera = {location = V.new{0,-5,0},
              point_at = V.new{0,0,0},