intersect: special case for zero rays

Author: victorpoughon

src/torchlensmaker/core/intersect.py

@@ -50,6 +50,10 @@ def intersect(
     assert P.shape[1] == V.shape[1]
     assert P.shape[1] in {2, 3}
 
+    # Special case for zero rays
+    if P.shape[0] == 0:
+        return torch.zeros_like(P), torch.zeros_like(V), torch.full((P.shape[0],), False)
+
     # Convert rays to surface local frame
     Ps = transform.inverse_points(P)
     Vs = transform.inverse_vectors(V)

src/torchlensmaker/core/sag_functions.py

@@ -451,6 +451,13 @@ def __init__(self, coefficients: Tensor, normalize: bool = False):
         self.p = torch.arange(self.coefficients.shape[0])
         self.q = torch.arange(self.coefficients.shape[1])
 
+    def parameters(self) -> dict[str, nn.Parameter]:
+        return (
+            {"coefficients": self.coefficients}
+            if isinstance(self.coefficients, nn.Parameter)
+            else {}
+        )
+
     def unnorm(self, tau: Tensor) -> Tensor:
         if self.normalize:
             taup = torch.pow(tau, self.p)
@@ -459,13 +466,10 @@ def unnorm(self, tau: Tensor) -> Tensor:
             return self.coefficients * tau / denom
         else:
             return self.coefficients
-
-    def parameters(self) -> dict[str, nn.Parameter]:
-        return (
-            {"coefficients": self.coefficients}
-            if isinstance(self.coefficients, nn.Parameter)
-            else {}
-        )
+    
+    def bounds(self, tau: Tensor) -> Tensor:
+        # TODO
+        return torch.tensor([-1., 1., 1.], dtype=self.coefficients.dtype)
 
     def G(self, y: Tensor, z: Tensor, tau: Tensor) -> Tensor:
         C = bbroad(self.unnorm(tau), y.dim())

src/torchlensmaker/core/surfaces.py

@@ -571,8 +571,8 @@ def __init__(
 
 
 # TODO
-class Conic(SagSurface):
-    ...
+class Conic(SagSurface): ...
+
 
 class Asphere(SagSurface):
     """