star-camera

commit a48466167528bd2e8d2f4c5bebf0f4b54c19d326
parent 30ba1221268c7ecf0d4d7d92909dd1fbe2c59c44
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Tue, 27 Jul 2021 09:14:13 +0200

Test the ray generation for the thin lens model

Diffstat:
M
src/scam_perspective.c
 | 
2
+-
M
src/test_scam_pinhole.c
 | 
1
+
M
src/test_scam_thin_lens.c
 | 
46
++++++++++++++++++++++++++++++++++++++--------

3 files changed, 40 insertions(+), 9 deletions(-)
diff --git a/src/scam_perspective.c b/src/scam_perspective.c
@@ -221,7 +221,7 @@ scam_create_perspective
   res = setup_perspective(cam, args);
   if(res != RES_OK) goto error;
 
-  exit:
+exit:
   if(out_cam) *out_cam = cam;
   return res;
 error:
diff --git a/src/test_scam_pinhole.c b/src/test_scam_pinhole.c
@@ -154,6 +154,7 @@ main(int argc, char** argv)
     CHK(d3_eq(ray.org, args.position));
 
     /* Check that the generated ray is in the view frustum */
+    CHK(d3_is_normalized(ray.dir));
     cos_ray_axis_x = d3_dot(ray.dir, axis_x);
     cos_ray_axis_y = d3_dot(ray.dir, axis_y);
     cos_ray_axis_z = d3_dot(ray.dir, axis_z);
diff --git a/src/test_scam_thin_lens.c b/src/test_scam_thin_lens.c
@@ -18,7 +18,9 @@
 #include "scam.h"
 #include "test_scam_utils.h"
 
+#include <rsys/double2.h>
 #include <rsys/double3.h>
+#include <rsys/double33.h>
 #include <rsys/math.h>
 #include <rsys/mem_allocator.h>
 
@@ -31,6 +33,7 @@ main(int argc, char** argv)
   struct scam_ray ray = SCAM_RAY_NULL;
   const size_t nsamps = 1000;
   size_t i;
+  double transform[9];
   double axis_x[3];
   double axis_y[3];
   double axis_z[3];
@@ -95,6 +98,12 @@ main(int argc, char** argv)
   sin_hori_hfov = sin(hori_hfov);
   sin_vert_hfov = sin(args.field_of_view*0.5);
 
+  /* Compute the world to camera space transformation */
+  d3_set(transform + 0, axis_x);
+  d3_set(transform + 3, axis_y);
+  d3_set(transform + 6, axis_z);
+  d33_transpose(transform, transform);
+
   sample.lens[0] = nextafterf(0, -1);
   CHK(scam_generate_ray(cam, &sample, &ray) == RES_BAD_ARG);
   sample.lens[0] = 1;
@@ -112,22 +121,43 @@ main(int argc, char** argv)
     double cos_ray_axis_x;
     double cos_ray_axis_y;
     double cos_ray_axis_z;
+    double dir[3];
+    double pos[3];
+    double dst;
+
     sample.film[0] = rand_canonical();
     sample.film[1] = rand_canonical();
     sample.lens[0] = rand_canonical();
     sample.lens[1] = rand_canonical();
     CHK(scam_generate_ray(cam, &sample, &ray) == RES_OK);
 
-    /* Check that the ray origin lies on the lens */
-    /*CHK(d3_eq(ray.org, args.position));*/
-
-    /* Check that the generated ray is in the view frustum */
-    /*cos_ray_axis_x = d3_dot(ray.dir, axis_x);
-    cos_ray_axis_y = d3_dot(ray.dir, axis_y);
-    cos_ray_axis_z = d3_dot(ray.dir, axis_z);
+    /* Transform the position in camera space */
+    d3_sub(pos, ray.org, args.position);
+    d33_muld3(pos, transform, pos);
+
+    /* Check that the sampled position lies onto the thin lens */
+    dst = d2_len(pos);
+    CHK(eq_eps(pos[2], 0, 1.e-6));
+    CHK(dst < args.lens_radius
+     || eq_eps(dst, args.lens_radius, args.lens_radius*1.e-6));
+
+    /* Compute the ray starting from the lens center and intersecting the focal
+     * plane at the same position of the generated ray */
+    pos[0] = ray.org[0] + ray.dir[0]*args.focal_distance;
+    pos[1] = ray.org[1] + ray.dir[1]*args.focal_distance;
+    pos[2] = ray.org[2] + ray.dir[2]*args.focal_distance;
+    CHK(d3_is_normalized(ray.dir));
+    d3_add(pos, ray.org, ray.dir);
+    d3_sub(dir, pos, args.position);
+    d3_normalize(dir, dir);
+
+    /* Check that the computed direction is in the view frustum */
+    cos_ray_axis_x = d3_dot(dir, axis_x);
+    cos_ray_axis_y = d3_dot(dir, axis_y);
+    cos_ray_axis_z = d3_dot(dir, axis_z);
     CHK(cos_ray_axis_z >= 0);
     CHK(cos_ray_axis_y <= sin_vert_hfov);
-    CHK(cos_ray_axis_x <= sin_hori_hfov);*/
+    CHK(cos_ray_axis_x <= sin_hori_hfov);
   }
 
   CHK(scam_ref_put(cam) == RES_OK);