raymarching tweaks + add overstepping

1 files changed, 21 insertions, 16 deletions

diff --git a/ray_marching.cginc b/ray_marching.cginc
index 513178b..4c7544e 100644
--- a/ray_marching.cginc
+++ b/ray_marching.cginc
@@ -24,7 +24,7 @@ void GetRoRd(v2f i, out float3 ro, out float3 rd) {
   rd = normalize(getObjPos(i) - obj_space_camera_pos);
 }
 
-RayMarchResult ray_march(v2f i) {
+void ray_march(inout v2f i) {
   float3 ro, rd;
   GetRoRd(i, ro, rd);
 
@@ -36,21 +36,25 @@ RayMarchResult ray_march(v2f i) {
   rd = normalize(rd_perp + rd_tan);
 #endif
 
-  const float kMinDist = 1e-4;
-  // TODO dial this in & parameterize
-  const float kMaxDist = 10;
-  // TODO parameterize
-  const uint kMaxIter = 30;
+  const float kMinDist = _Ray_Marching_Min_Dist;
+  const float kMaxDist = _Ray_Marching_Max_Dist;
+  const uint kMaxIter = _Ray_Marching_Max_Iter;
+  float d_cur;
   float d_acc = 0;
   for (uint ii = 0; ii < kMaxIter; ++ii) {
     float3 p = ro + rd * d_acc;
-    float d_cur = 1e9;
+    d_cur = 1e9;
 #if defined(_RAY_MARCHING_BALL_GRID)
-    float3 count = _Ray_Marching_Ball_Grid_Count;
+    float3 count = float3(_Ray_Marching_Ball_Grid_Count_X, _Ray_Marching_Ball_Grid_Count_Y, _Ray_Marching_Ball_Grid_Count_Z);
     d_cur = min(d_cur, map_ball_grid(p, count));
 #endif
+
+#if defined(_RAY_MARCHING_OVERSTEP)
+    d_cur *= _Ray_Marching_Overstepping_Factor;
+#endif
+
     d_acc += d_cur;
-    if (d_cur < kMinDist) {
+    if (abs(d_cur) < kMinDist) {
       break;
     }
     if (d_acc > kMaxDist) {
@@ -58,21 +62,22 @@ RayMarchResult ray_march(v2f i) {
     }
   }
 
+  if (abs(d_cur) > kMinDist) {
+    discard;
+  }
+
   // TODO clip / hit detection
   float3 lclPos = ro + rd * d_acc;
   float3 lclNorm;
   float3 lclTan;
 #if defined(_RAY_MARCHING_BALL_GRID)
-  float3 count = _Ray_Marching_Ball_Grid_Count;
+  float3 count = float3(_Ray_Marching_Ball_Grid_Count_X, _Ray_Marching_Ball_Grid_Count_Y, _Ray_Marching_Ball_Grid_Count_Z);
   map_ball_grid_normal(count, lclPos, lclNorm, lclTan);
 #endif
 
-  RayMarchResult res;
-  res.objPos = lclPos;
-  res.objNorm = lclNorm;
-  res.objTan = lclTan;
-
-  return res;
+  i.objPos = lclPos;
+  i.normal = lclNorm;
+  i.tangent.xyz = lclTan;
 }
 
 #endif  // __RAY_MARCHING_INC