diff options
Diffstat (limited to 'source/gameengine/Ketsji/KX_Camera.cpp')
| -rw-r--r-- | source/gameengine/Ketsji/KX_Camera.cpp | 75 |
1 files changed, 71 insertions, 4 deletions
diff --git a/source/gameengine/Ketsji/KX_Camera.cpp b/source/gameengine/Ketsji/KX_Camera.cpp index 53b3e348a36..fb91c793765 100644 --- a/source/gameengine/Ketsji/KX_Camera.cpp +++ b/source/gameengine/Ketsji/KX_Camera.cpp @@ -259,10 +259,75 @@ void KX_Camera::ExtractFrustumSphere() if (m_set_frustum_center) return; - // The most extreme points on the near and far plane. (normalized device coords) - MT_Vector4 hnear(1., 1., 0., 1.), hfar(1., 1., 1., 1.); + // compute sphere for the general case and not only symmetric frustum: + // the mirror code in ImageRender can use very asymmetric frustum. + // We will put the sphere center on the line that goes from origin to the center of the far clipping plane + // This is the optimal position if the frustum is symmetric or very asymmetric and probably close + // to optimal for the general case. The sphere center position is computed so that the distance to + // the near and far extreme frustum points are equal. + + // get the transformation matrix from device coordinate to camera coordinate MT_Matrix4x4 clip_camcs_matrix = m_projection_matrix; clip_camcs_matrix.invert(); + + // detect which of the corner of the far clipping plane is the farthest to the origin + MT_Vector4 nfar; // far point in device normalized coordinate + MT_Point3 farpoint; // most extreme far point in camera coordinate + MT_Point3 nearpoint;// most extreme near point in camera coordinate + MT_Point3 farcenter(0.,0.,0.);// center of far cliping plane in camera coordinate + MT_Scalar F=1.0, N; // square distance of far and near point to origin + MT_Scalar f, n; // distance of far and near point to z axis. f is always > 0 but n can be < 0 + MT_Scalar e, s; // far and near clipping distance (<0) + MT_Scalar c; // slope of center line = distance of far clipping center to z axis / far clipping distance + MT_Scalar z; // projection of sphere center on z axis (<0) + // tmp value + MT_Vector4 npoint(1., 1., 1., 1.); + MT_Vector4 hpoint; + MT_Point3 point; + MT_Scalar len; + for (int i=0; i<4; i++) + { + hpoint = clip_camcs_matrix*npoint; + point.setValue(hpoint[0]/hpoint[3], hpoint[1]/hpoint[3], hpoint[2]/hpoint[3]); + len = point.dot(point); + if (len > F) + { + nfar = npoint; + farpoint = point; + F = len; + } + // rotate by 90 degree along the z axis to walk through the 4 extreme points of the far clipping plane + len = npoint[0]; + npoint[0] = -npoint[1]; + npoint[1] = len; + farcenter += point; + } + // the far center is the average of the far clipping points + farcenter *= 0.25; + // the extreme near point is the opposite point on the near clipping plane + nfar.setValue(-nfar[0], -nfar[1], -1., 1.); + nfar = clip_camcs_matrix*nfar; + nearpoint.setValue(nfar[0]/nfar[3], nfar[1]/nfar[3], nfar[2]/nfar[3]); + N = nearpoint.dot(nearpoint); + e = farpoint[2]; + s = nearpoint[2]; + // projection on XY plane for distance to axis computation + MT_Point2 farxy(farpoint[0], farpoint[1]); + // f is forced positive by construction + f = farxy.length(); + // get corresponding point on the near plane + farxy *= s/e; + // this formula preserve the sign of n + n = f*s/e - MT_Point2(nearpoint[0]-farxy[0], nearpoint[1]-farxy[1]).length(); + c = MT_Point2(farcenter[0], farcenter[1]).length()/e; + // the big formula, it simplifies to (F-N)/(2(e-s)) for the symmetric case + z = (F-N)/(2.0*(e-s+c*(f-n))); + m_frustum_center = MT_Point3(farcenter[0]*z/e, farcenter[1]*z/e, z); + m_frustum_radius = m_frustum_center.distance(farpoint); + +#if 0 + // The most extreme points on the near and far plane. (normalized device coords) + MT_Vector4 hnear(1., 1., 0., 1.), hfar(1., 1., 1., 1.); // Transform to hom camera local space hnear = clip_camcs_matrix*hnear; @@ -273,10 +338,12 @@ void KX_Camera::ExtractFrustumSphere() MT_Point3 farpoint(hfar[0]/hfar[3], hfar[1]/hfar[3], hfar[2]/hfar[3]); // Compute center + // don't use camera data in case the user specifies the matrix directly m_frustum_center = MT_Point3(0., 0., - (nearpoint.dot(nearpoint) - farpoint.dot(farpoint))/(2.0*(m_camdata.m_clipend - m_camdata.m_clipstart))); + (nearpoint.dot(nearpoint) - farpoint.dot(farpoint))/(2.0*(nearpoint[2]-farpoint[2] /*m_camdata.m_clipend - m_camdata.m_clipstart*/))); m_frustum_radius = m_frustum_center.distance(farpoint); - +#endif + // Transform to world space. m_frustum_center = GetCameraToWorld()(m_frustum_center); m_frustum_radius /= fabs(NodeGetWorldScaling()[NodeGetWorldScaling().closestAxis()]); |