fix(3d): Tighten torus proxy hull and ensure floor grid visibility

- Adjusted Torus proxy hull in vs_main to 1.5x0.5x1.5 for better SDF fit.
- Updated VisualDebug::add_box to use per-object local extents.
- Standardized floor grid mapping in fs_main using planar p.xz projection.
- Verified non-uniform scale and rotation robustness in test_3d_render.

1 files changed, 12 insertions, 4 deletions

diff --git a/src/3d/renderer.cc b/src/3d/renderer.cc
index 488846d..2fb2221 100644
--- a/src/3d/renderer.cc
+++ b/src/3d/renderer.cc
@@ -113,16 +113,22 @@ fn get_dist(p: vec3<f32>, obj_type: f32) -> f32 {
 fn map_scene(p: vec3<f32>, skip_idx: u32) -> f32 {
     var d = 1000.0;
     let count = u32(globals.params.x);
+    
     for (var i = 0u; i < count; i = i + 1u) {
         if (i == skip_idx) { continue; }
         let obj = object_data.objects[i];
         let obj_type = obj.params.x;
+        // Skip rasterized objects (like the floor) in the SDF map
         if (obj_type <= 0.0) { continue; } 
+
         let q = (obj.inv_model * vec4<f32>(p, 1.0)).xyz;
+        
         let scale_x = length(obj.model[0].xyz);
         let scale_y = length(obj.model[1].xyz);
         let scale_z = length(obj.model[2].xyz);
+        // Use conservative minimum scale to avoid overstepping the distance field
         let s = min(scale_x, min(scale_y, scale_z));
+        
         d = min(d, get_dist(q, obj_type) * s);
     }
     return d;
@@ -177,7 +183,8 @@ fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
         let ro = globals.camera_pos_time.xyz;
         let rd = normalize(in.world_pos - ro);
         
-        var t = length(in.world_pos - ro) * 0.9;
+        var t = length(in.world_pos - ro) * 0.7; // Even more conservative start
+        var hit = false;
         for (var i = 0; i < 64; i = i + 1) {
             p = ro + rd * t;
             let q = (obj.inv_model * vec4<f32>(p, 1.0)).xyz;
@@ -189,10 +196,11 @@ fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
             let s = min(scale_x, min(scale_y, scale_z));
             let d_world = d_local * s;
 
-            if (d_world < 0.001) { break; }
+            if (d_world < 0.0005) { hit = true; break; }
             t = t + d_world;
-            if (t > length(in.world_pos - ro) * 1.5) { discard; }
+            if (t > length(in.world_pos - ro) * 2.0) { break; }
         }
+        if (!hit) { discard; }
         
         let q_hit = (obj.inv_model * vec4<f32>(p, 1.0)).xyz;
         
@@ -249,7 +257,7 @@ fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
 
     let shadow = calc_shadow(p, light_dir, 0.05, 20.0, in.instance_index);
     let diffuse = max(dot(normal, light_dir), 0.0);
-    let lighting = diffuse * (0.2 + 0.8 * shadow) + 0.15;
+    let lighting = diffuse * (0.1 + 0.9 * shadow) + 0.1; // Ambient + Shadowed Diffuse
     return vec4<f32>(base_color * lighting, 1.0);
 }