Add getters for camera parameters #1419 #2767

Dtsitos · 2026-01-02T12:21:42Z

Describe your changes

This PR adds read-only getters to the camera API to retrieve derived world-space
camera parameters (azimuth, elevation, and distance).

The values are computed from the camera position and focal point and do not
modify camera state. This enables external applications and bindings to query
camera orientation consistently without duplicating math.

No existing behavior is changed.

Original PR: #2724

Issue ticket number and link if any

Fixes #1419

Checklist for finalizing the PR

I have performed a self-review of my code
I have added tests for new features and bugfixes
I have added documentation for new features
If it is a modifying the libf3d API, I have updated bindings
If it is a modifying the .github/workflows/versions.json, I have updated docker_timestamp

Continuous integration

Please write a comment to run CI, eg: \ci fast.
See here for more info.

…ickly for further processing (cherry picked from commit 935740b)

(cherry picked from commit c589cd3)

…n to compute the distance from the camera position to the focal point (cherry picked from commit a54c71e)

(cherry picked from commit af3407a)

(cherry picked from commit 3f8671b)

…mproved getWorldAzimuth using SignedAngleBetweenVectors

github-actions · 2026-01-02T12:21:50Z

You are modifying libf3d public API! ⚠️Please update bindings accordingly⚠️!
You can find them in their respective directories: c, python, java, webassembly.

Dtsitos · 2026-01-02T12:22:07Z

I think this should be correct now, will work on better testing ASAP

snoyer · 2026-01-02T15:46:22Z

library/src/camera_impl.cxx

+  // Elevation is angle above the horizontal plane
+  double dot = vtkMath::Dot(view.data(), up);
+  dot = std::clamp(dot, -1.0, 1.0);
+
+  return vtkMath::DegreesFromRadians(std::asin(dot));


Would be nice to check if that can be done with AngleBetweenVectors to avoid the raw trig. Maybe something like 90° - angle_between(view, up)?

snoyer · 2026-01-02T15:47:22Z

library/src/camera_impl.cxx

+  static constexpr double EPS = 128 * std::numeric_limits<double>::epsilon();
+  if (vtkMath::Norm(horizontal.data()) < EPS)
+  {
+    return 0.0;
+  }
+
+  vtkMath::Normalize(horizontal.data());


Once you've got the tests you can double check if this is actually needed

…omplex scenarios

mwestphal · 2026-01-03T15:30:51Z

please let us know when its ready for review @Dtsitos

Dtsitos · 2026-01-04T14:18:26Z

@mwestphal Hello there, I have implemented all the bindings and some basic testing for them. Full disclosure, I have never worked with bindings again and mostly deduced what to do based on the patterns from the existing implementations. Thank you for your patience

mwestphal · 2026-01-04T17:45:16Z

@mwestphal Hello there, I have implemented all the bindings and some basic testing for them. Full disclosure, I have never worked with bindings again and mostly deduced what to do based on the patterns from the existing implementations. Thank you for your patience

Thats perfectly fine and it looks good to me :)

mwestphal · 2026-01-04T17:45:58Z

@Dtsitos can you adress and resolve the suggestions made by @snoyer above ?
If you did adress them already, please resolve the discussions.

mwestphal · 2026-01-04T17:46:11Z

\ci full

github-actions · 2026-01-04T17:46:48Z

Style Checks CI failed:

diff --git a/library/src/camera_impl.cxx b/library/src/camera_impl.cxx
index fb8d8ee..5e35fb7 100644
--- a/library/src/camera_impl.cxx
+++ b/library/src/camera_impl.cxx
@@ -1,12 +1,11 @@
 #include "camera_impl.h"
 
+#include <cmath>
 #include <vtkCamera.h>
 #include <vtkMatrix4x4.h>
 #include <vtkRenderWindow.h>
 #include <vtkRenderer.h>
 #include <vtkVersion.h>
-#include <cmath>
-
 
 namespace f3d::detail
 {
@@ -106,7 +105,7 @@ void camera_impl::getFocalPoint(point3_t& foc) const
 }
 
 //----------------------------------------------------------------------------
-  void camera_impl::getPositionToFocalVector(vector3_t& vec) const
+void camera_impl::getPositionToFocalVector(vector3_t& vec) const
 {
   point3_t pos, focal;
   this->getPosition(pos);
@@ -116,7 +115,7 @@ void camera_impl::getFocalPoint(point3_t& foc) const
 }
 
 //----------------------------------------------------------------------------
-  double camera_impl::getWorldAzimuth() const
+double camera_impl::getWorldAzimuth() const
 {
   vector3_t view;
   this->getPositionToFocalVector(view);
@@ -145,11 +144,10 @@ void camera_impl::getFocalPoint(point3_t& foc) const
   double angleRad = vtkMath::SignedAngleBetweenVectors(right, horizontal.data(), up);
 
   return vtkMath::DegreesFromRadians(angleRad);
-
 }
 
 //----------------------------------------------------------------------------
-  double camera_impl::getWorldElevation() const
+double camera_impl::getWorldElevation() const
 {
   vector3_t view;
   this->getPositionToFocalVector(view);
@@ -166,7 +164,7 @@ void camera_impl::getFocalPoint(point3_t& foc) const
 }
 
 //----------------------------------------------------------------------------
-  double camera_impl::getDistance() const
+double camera_impl::getDistance() const
 {
   vector3_t v;
   this->getPositionToFocalVector(v);
diff --git a/library/testing/TestSDKCamera.cxx b/library/testing/TestSDKCamera.cxx
index 74670fc..7bb46e0 100644
--- a/library/testing/TestSDKCamera.cxx
+++ b/library/testing/TestSDKCamera.cxx
@@ -243,7 +243,8 @@ int TestSDKCamera([[maybe_unused]] int argc, [[maybe_unused]] char* argv[])
 
   if (!compareDouble(elevation, 0.0))
   {
-    std::cerr << "getWorldElevation (horizontal) is not behaving as expected: " << elevation << "\n";
+    std::cerr << "getWorldElevation (horizontal) is not behaving as expected: " << elevation
+              << "\n";
     return EXIT_FAILURE;
   }
 
@@ -258,13 +259,15 @@ int TestSDKCamera([[maybe_unused]] int argc, [[maybe_unused]] char* argv[])
 
   if (!compareDouble(distance, std::sqrt(11.0 * 11.0 + 11.0 * 11.0)))
   {
-    std::cerr << "getDistance (positive elevation) is not behaving as expected: " << distance << "\n";
+    std::cerr << "getDistance (positive elevation) is not behaving as expected: " << distance
+              << "\n";
     return EXIT_FAILURE;
   }
 
   if (!compareDouble(azimuth, 90.0))
   {
-    std::cerr << "getWorldAzimuth (positive elevation) is not behaving as expected: " << azimuth << "\n";
+    std::cerr << "getWorldAzimuth (positive elevation) is not behaving as expected: " << azimuth
+              << "\n";
     return EXIT_FAILURE;
   }
 
@@ -286,7 +289,8 @@ int TestSDKCamera([[maybe_unused]] int argc, [[maybe_unused]] char* argv[])
 
   if (!compareDouble(distance, std::sqrt(11.0 * 11.0 + 11.0 * 11.0)))
   {
-    std::cerr << "getDistance (negative elevation) is not behaving as expected: " << distance << "\n";
+    std::cerr << "getDistance (negative elevation) is not behaving as expected: " << distance
+              << "\n";
     return EXIT_FAILURE;
   }
 
@@ -341,15 +345,14 @@ int TestSDKCamera([[maybe_unused]] int argc, [[maybe_unused]] char* argv[])
 
   if (!compareDouble(azimuth, 0.0))
   {
-    std::cerr << "getWorldAzimuth with zero direction vector should return 0: "
-              << azimuth << "\n";
+    std::cerr << "getWorldAzimuth with zero direction vector should return 0: " << azimuth << "\n";
     return EXIT_FAILURE;
   }
 
   if (!compareDouble(elevation, 0.0))
   {
-    std::cerr << "getWorldElevation with zero direction vector should return 0: "
-              << elevation << "\n";
+    std::cerr << "getWorldElevation with zero direction vector should return 0: " << elevation
+              << "\n";
     return EXIT_FAILURE;
   }
 
@@ -363,15 +366,14 @@ int TestSDKCamera([[maybe_unused]] int argc, [[maybe_unused]] char* argv[])
 
   if (!compareDouble(azimuth, 0.0))
   {
-    std::cerr << "getWorldAzimuth with forward parallel to up should return 0: "
-              << azimuth << "\n";
+    std::cerr << "getWorldAzimuth with forward parallel to up should return 0: " << azimuth << "\n";
     return EXIT_FAILURE;
   }
 
   if (!compareDouble(elevation, 90.0))
   {
-    std::cerr << "getWorldElevation with forward parallel to up should be 90: "
-              << elevation << "\n";
+    std::cerr << "getWorldElevation with forward parallel to up should be 90: " << elevation
+              << "\n";
     return EXIT_FAILURE;
   }

Dtsitos added 6 commits January 2, 2026 12:43

added distance, azimuth and elevation API for returning the values qu…

f98316e

…ickly for further processing (cherry picked from commit 935740b)

Updated implementation to not use M_PI and added comments to camera.h

2f973ca

(cherry picked from commit c589cd3)

Clarified naming for new functions and added a private helper functio…

1606829

…n to compute the distance from the camera position to the focal point (cherry picked from commit a54c71e)

Changed getters to be enviromentally aware

eea3a9a

(cherry picked from commit af3407a)

Added tests for three new getters

ba87665

(cherry picked from commit 3f8671b)

Fixed typo in camera.h, improved documentation in camera_impl.h and i…

0969dd4

…mproved getWorldAzimuth using SignedAngleBetweenVectors

mwestphal mentioned this pull request Jan 2, 2026

Add getters for camera parameters #1419 #2724

Closed

5 tasks

snoyer reviewed Jan 2, 2026

View reviewed changes

Added improved testing at TestSDKCamera.cxx for edge cases and more c…

df4f0b8

…omplex scenarios

Dtsitos added 2 commits January 4, 2026 13:32

Added C bindings and testing

e69e067

Added Python, Java and WebAssembly bindings and testing

0c1b294

mwestphal added the ci:full label Jan 4, 2026

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Describe your changes

Issue ticket number and link if any

Checklist for finalizing the PR

Continuous integration

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Dtsitos commented Jan 2, 2026 •

edited by mwestphal

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