Cleanup: Fix various divisions by zero reported by ASAN

Pull Request: https://projects.blender.org/blender/blender/pulls/135326

Author: brechtvl

intern/cycles/bvh/binning.cpp

@@ -77,7 +77,7 @@ BVHObjectBinning::BVHObjectBinning(const BVHRange &job,
 
   /* compute number of bins to use and precompute scaling factor for binning */
   num_bins = min(size_t(MAX_BINS), size_t(4.0f + 0.05f * size()));
-  scale = reciprocal(cent_bounds_.size()) * make_float3((float)num_bins);
+  scale = safe_divide(cent_bounds_.size(), make_float3((float)num_bins));
 
   /* initialize binning counter and bounds */
   BoundBox bin_bounds[MAX_BINS][4]; /* bounds for every bin in every dimension */

intern/cycles/kernel/closure/bsdf_microfacet.h

@@ -677,7 +677,7 @@ ccl_device int bsdf_microfacet_sample(KernelGlobals kg,
   }
 
   const float m_eta = bsdf->ior;
-  const float m_inv_eta = 1.0f / bsdf->ior;
+  const float m_inv_eta = safe_divide(1.0f, bsdf->ior);
   const float alpha_x = bsdf->alpha_x;
   const float alpha_y = bsdf->alpha_y;
   bool m_singular = !bsdf_microfacet_eval_flag(bsdf);

intern/cycles/kernel/geom/shader_data.h

@@ -274,6 +274,9 @@ ccl_device void shader_setup_from_displace(KernelGlobals kg,
                            0.5f,
                            !(kernel_data_fetch(object_flag, object) & SD_OBJECT_TRANSFORM_APPLIED),
                            false);
+
+  /* Assign some incoming direction to avoid division by zero. */
+  sd->wi = sd->N;
 }
 
 /* ShaderData setup for point on curve. */
@@ -321,7 +324,7 @@ ccl_device void shader_setup_from_curve(KernelGlobals kg,
   P_curve[3] = kernel_data_fetch(curve_keys, kb);
 
   /* Interpolate position and tangent. */
-  sd->P = make_float3(catmull_rom_basis_derivative(P_curve, sd->u));
+  sd->P = make_float3(catmull_rom_basis_eval(P_curve, sd->u));
 #  ifdef __DPDU__
   sd->dPdu = make_float3(catmull_rom_basis_derivative(P_curve, sd->u));
 #  endif
@@ -334,12 +337,12 @@ ccl_device void shader_setup_from_curve(KernelGlobals kg,
 #  endif
   }
 
-  /* No view direction, normals or bitangent. */
-  sd->wi = zero_float3();
-  sd->N = zero_float3();
-  sd->Ng = zero_float3();
+  /* Pick arbitrary view direction, normals and bitangent to avoid NaNs elsewhere. */
+  sd->wi = normalize(cross(make_float3(0, 1, 0), sd->dPdu));
+  sd->N = sd->wi;
+  sd->Ng = sd->wi;
 #  ifdef __DPDU__
-  sd->dPdv = zero_float3();
+  sd->dPdv = cross(sd->dPdu, sd->Ng);
 #  endif
 
   /* No ray differentials currently. */

intern/cycles/kernel/integrator/intersect_volume_stack.h

@@ -28,7 +28,7 @@ ccl_device void integrator_volume_stack_update_for_subsurface(KernelGlobals kg,
 
   Ray volume_ray ccl_optional_struct_init;
   volume_ray.P = from_P;
-  volume_ray.D = normalize_len(to_P - from_P, &volume_ray.tmax);
+  volume_ray.D = safe_normalize_len(to_P - from_P, &volume_ray.tmax);
   volume_ray.tmin = 0.0f;
   volume_ray.self.object = INTEGRATOR_STATE(state, isect, object);
   volume_ray.self.prim = INTEGRATOR_STATE(state, isect, prim);

intern/cycles/kernel/light/area.h

@@ -67,7 +67,7 @@ ccl_device_inline float area_light_rect_sample(const float3 P,
      * the extra +pi that would remain in the expression for au can be removed by flipping the sign
      * of cos(au) and sin(au), which also cancels if we flip the sign of b1 in the fu term. */
     const float au = rand.x * S + g2 + g3;
-    const float fu = (cosf(au) * b0 + b1) / sinf(au);
+    const float fu = safe_divide(cosf(au) * b0 + b1, sinf(au));
     float cu = copysignf(1.0f / sqrtf(fu * fu + b0sq), fu);
     cu = clamp(cu, -1.0f, 1.0f);
     /* Compute xu. */
@@ -96,7 +96,7 @@ ccl_device_inline float area_light_rect_sample(const float3 P,
      * needed for the case where the light is viewed from grazing angles, see e.g. #98930.
      */
     const float t = len(dir);
-    return -t * t * t / (z0 * len_u * len_v);
+    return safe_divide(-t * t * t, (z0 * len_u * len_v));
   }
   return 1.0f / S;
 }
@@ -306,7 +306,7 @@ ccl_device_inline bool area_light_eval(const ccl_global KernelLight *klight,
 
   if (sample_coord) {
     *light_P = light_P_new;
-    ls->D = normalize_len(*light_P - ray_P, &ls->t);
+    ls->D = safe_normalize_len(*light_P - ray_P, &ls->t);
   }
 
   /* Convert radiant flux to radiance. */
@@ -384,7 +384,7 @@ ccl_device_forceinline void area_light_mnee_sample_update(const ccl_global Kerne
     area_light_eval<false>(klight, P, &ls->P, ls, zero_float2(), true);
   }
   else {
-    ls->D = normalize_len(ls->P - P, &ls->t);
+    ls->D = safe_normalize_len(ls->P - P, &ls->t);
     area_light_eval<false>(klight, P, &ls->P, ls, zero_float2(), false);
     /* Convert pdf to be in area measure. */
     ls->pdf /= light_pdf_area_to_solid_angle(ls->Ng, -ls->D, ls->t);

intern/cycles/kernel/light/point.h

@@ -66,7 +66,7 @@ ccl_device_inline bool point_light_sample(KernelGlobals kg,
       ls->P += disk_light_sample(lightN, rand) * klight->spot.radius;
     }
 
-    ls->D = normalize_len(ls->P - P, &ls->t);
+    ls->D = safe_normalize_len(ls->P - P, &ls->t);
     ls->Ng = -ls->D;
 
     /* PDF. */
@@ -102,7 +102,7 @@ ccl_device_forceinline void point_light_mnee_sample_update(KernelGlobals kg,
                                                            const float3 N,
                                                            const uint32_t path_flag)
 {
-  ls->D = normalize_len(ls->P - P, &ls->t);
+  ls->D = safe_normalize_len(ls->P - P, &ls->t);
 
   const float radius = klight->spot.radius;
 

intern/cycles/kernel/light/sample.h

@@ -233,7 +233,7 @@ ccl_device_inline void shadow_ray_setup(const ccl_private ShaderData *ccl_restri
     else {
       /* other lights, avoid self-intersection */
       ray->D = ls->P - P;
-      ray->D = normalize_len(ray->D, &ray->tmax);
+      ray->D = safe_normalize_len(ray->D, &ray->tmax);
     }
   }
   else {

intern/cycles/kernel/light/spot.h

@@ -133,7 +133,7 @@ ccl_device_inline bool spot_light_sample(KernelGlobals kg,
       ls->P += disk_light_sample(lightN, rand) * klight->spot.radius;
     }
 
-    ls->D = normalize_len(ls->P - P, &ls->t);
+    ls->D = safe_normalize_len(ls->P - P, &ls->t);
     ls->Ng = -ls->D;
 
     /* Attenuation. */
@@ -177,7 +177,7 @@ ccl_device_forceinline void spot_light_mnee_sample_update(KernelGlobals kg,
                                                           const float3 N,
                                                           const uint32_t path_flag)
 {
-  ls->D = normalize_len(ls->P - P, &ls->t);
+  ls->D = safe_normalize_len(ls->P - P, &ls->t);
 
   ls->eval_fac = klight->spot.eval_fac;
 

intern/cycles/scene/camera.cpp

@@ -312,11 +312,11 @@ void Camera::update(Scene *scene)
 
   if (camera_type == CAMERA_PERSPECTIVE) {
     float3 v = transform_perspective(&full_rastertocamera,
-                                     make_float3(full_width, full_height, 1.0f));
+                                     make_float3(full_width, full_height, 0.0f));
     frustum_right_normal = normalize(make_float3(v.z, 0.0f, -v.x));
     frustum_top_normal = normalize(make_float3(0.0f, v.z, -v.y));
 
-    v = transform_perspective(&full_rastertocamera, make_float3(0.0f, 0.0f, 1.0f));
+    v = transform_perspective(&full_rastertocamera, make_float3(0.0f, 0.0f, 0.0f));
     frustum_left_normal = normalize(make_float3(-v.z, 0.0f, v.x));
     frustum_bottom_normal = normalize(make_float3(0.0f, -v.z, v.y));
   }