Fix wrong Z check in OgreWideAngleCamera::Project3d (#746)

The matrix returned by Ogre::Camera::getProjectionMatrix has Z in range [-1; 1], not range [0; 1] This means we can't do pos.z > 0. We must do pos.z / pos.w > -1 Additionally, we must check against against z < 1; otherwise the point may get picked by the wrong face (and fail tests). Signed-off-by: Matias N. Goldberg <[email protected]>
gazebosim · Oct 30, 2022 · fcd52be · fcd52be
1 parent b197260
commit fcd52be
Showing 1 changed file with 5 additions and 2 deletions.
diff --git a/ogre/src/OgreWideAngleCamera.cc b/ogre/src/OgreWideAngleCamera.cc
@@ -505,8 +505,11 @@ math::Vector3d OgreWideAngleCamera::Project3d(
     auto pos = viewProj * Ogre::Vector4(OgreConversions::Convert(_pt));
     pos.x /= pos.w;
     pos.y /= pos.w;
-    // check if point is visible
-    if (std::fabs(pos.x) <= 1 && std::fabs(pos.y) <= 1 && pos.z > 0)
+    // check if point is visible.
+    // pos.z is in range [-w; w] so we check if it's > -w then
+    // it means it's in front of us.
+    if (std::fabs(pos.x) <= 1 && std::fabs(pos.y) <= 1 &&
+        pos.z > -std::fabs(pos.w))
     {
       // determine dir vector to projected point from env camera
       // work in y up, z forward, x right clip space