Correct for clockwise vs. counter clockwise computation of dp{du,dv}

Author: ojhunt

.DS_Store

@@ -228,10 +228,37 @@ impl Scene {
     let material = self.get_material(fragment.material);
     let surface = material.compute_surface_properties(self, ray, &fragment);
 
-    if false {
-      return ((fragment.normal + Vector::splat(1.0)) * 0.5, collision.distance);
+    match 0 {
+      1 => {
+        return ((fragment.normal + Vector::splat(1.0)) * 0.5, collision.distance);
+      }
+      2 => {
+        return ((fragment.true_normal + Vector::splat(1.0)) * 0.5, collision.distance);
+      }
+      3 => {
+        return ((surface.normal + Vector::splat(1.0)) * 0.5, collision.distance);
+      }
+      4 => {
+        let uv = fragment.uv;
+        return (
+          (Vector::vector(uv.0, uv.1, 0.0) + Vector::splat(1.0)) * 0.5,
+          collision.distance,
+        );
+      }
+      5 => {
+        return ((fragment.dpdu + Vector::splat(1.0)) * 0.5, collision.distance);
+      }
+      6 => {
+        return ((fragment.dpdv + Vector::splat(1.0)) * 0.5, collision.distance);
+      }
+      7 => {
+        return (
+          Vector::vector(0.7, 0.7, 0.7) * surface.normal.dot(Vector::vector(1.0, 1.0, 0.0).normalize()).max(0.0),
+          collision.distance,
+        );
+      }
+      _ => {}
     }
-
     // let ambient_colour = Vector::from(surface.ambient_colour);
     let mut diffuse_colour = Vector::from(surface.diffuse_colour);
     if let Some(emission) = surface.emissive_colour {

src/scene.rs

@@ -118,24 +118,24 @@ impl Shadable for Triangle {
 
         let uv_edge0 = t1 - t0;
         let uv_edge1 = t2 - t0;
-        let determinant = uv_edge0.0 * uv_edge1.1 - uv_edge0.1 * uv_edge1.0;
+        let determinant = (uv_edge0.0 * uv_edge1.1 - uv_edge0.1 * uv_edge1.0).abs();
         if determinant == 0.0 {
           let uv_edge0 = t0 - t1;
           let uv_edge1 = t2 - t1;
-          let determinant = uv_edge0.0 * uv_edge1.1 - uv_edge0.1 * uv_edge1.0;
+          let determinant = (uv_edge0.0 * uv_edge1.1 - uv_edge0.1 * uv_edge1.0).abs();
           if determinant != 0. {
             let edge0 = -self.edges[0];
             let edge1 = self.edges[1] - self.edges[0];
-            dpdu = ((uv_edge1.1 * edge0 - uv_edge0.1 * edge1) * (1.0 / determinant)).normalize();
+            dpdu = Vector::vector(0.0, 1.0, 0.0); //((uv_edge1.1 * edge0 - uv_edge0.1 * edge1) * (1.0 / determinant)).normalize();
             dpdv = ((uv_edge0.0 * edge1 - uv_edge1.0 * edge0) * (1.0 / determinant)).normalize();
           } else {
             let uv_edge0 = t0 - t2;
             let uv_edge1 = t1 - t2;
             let edge0 = -self.edges[1];
             let edge1 = self.edges[0] - self.edges[1];
-            let determinant = uv_edge0.0 * uv_edge1.1 - uv_edge0.1 * uv_edge1.0;
+            let determinant = (uv_edge0.0 * uv_edge1.1 - uv_edge0.1 * uv_edge1.0).abs();
             if determinant != 0.0 {
-              dpdu = ((uv_edge1.1 * edge0 - uv_edge0.1 * edge1) * (1.0 / determinant)).normalize();
+              dpdu = Vector::vector(1.0, 0.0, 0.0); //((uv_edge1.1 * edge0 - uv_edge0.1 * edge1) * (1.0 / determinant)).normalize();
               dpdv = ((uv_edge0.0 * edge1 - uv_edge1.0 * edge0) * (1.0 / determinant)).normalize();
             }
           }