VideoTexture.ImageMirror: if the mirror is horizontal in mesh coord, take the Y axis as the up direction for the UV map. If the mirror is not perfectly vertical(horizontal), the projection of the Z(Y) axis on the mirror plane is the mirror Up direction.

1 files changed, 24 insertions, 10 deletions

diff --git a/source/gameengine/VideoTexture/ImageRender.cpp b/source/gameengine/VideoTexture/ImageRender.cpp
index 1bf970babf0..58697ed3cc7 100644
--- a/source/gameengine/VideoTexture/ImageRender.cpp
+++ b/source/gameengine/VideoTexture/ImageRender.cpp
@@ -539,8 +539,9 @@ ImageRender::ImageRender (KX_Scene * scene, KX_GameObject * observer, KX_GameObj
     float mirrorArea = 0.f;
     float mirrorNormal[3] = {0.f, 0.f, 0.f};
     float mirrorUp[3];
-    float dist, vec[3];
+    float dist, vec[3], axis[3];
     float zaxis[3] = {0.f, 0.f, 1.f};
+    float yaxis[3] = {0.f, 1.f, 0.f};
     float mirrorMat[3][3];
     float left, right, top, bottom, back;
 	
@@ -602,23 +603,36 @@ ImageRender::ImageRender (KX_Scene * scene, KX_GameObject * observer, KX_GameObj
         THRWEXCP(MirrorNormalInvalid, S_OK);
     }
     // the mirror plane has an equation of the type ax+by+cz = d where (a,b,c) is the normal vector
-    // mirror up direction is the projection of Z on the plane
-    // scalar product between normal and Z axis
-    dist = Inpf(mirrorNormal, zaxis);
-    if (dist < FLT_EPSILON)
+	// if the mirror is more vertical then horizontal, the Z axis is the up direction.
+	// otherwise the Y axis is the up direction.
+	// If the mirror is not perfectly vertical(horizontal), the Z(Y) axis projection on the mirror
+	// plan by the normal will be the up direction.
+	if (fabs(mirrorNormal[2]) > fabs(mirrorNormal[1]) &&
+		fabs(mirrorNormal[2]) > fabs(mirrorNormal[0]))
+	{
+		// the mirror is more horizontal than vertical
+        VecCopyf(axis, yaxis);
+	}
+	else
+	{
+		// the mirror is more vertical than horizontal
+        VecCopyf(axis, zaxis);
+	}
+    dist = Inpf(mirrorNormal, axis);
+    if (fabs(dist) < FLT_EPSILON)
     {
-        // the mirror is already vertical
-        VecCopyf(mirrorUp, zaxis);
+        // the mirror is already fully aligned with up axis
+        VecCopyf(mirrorUp, axis);
     }
     else
     {
-        // projection of Z to normal
+        // projection of axis to mirror plane through normal
         VecCopyf(vec, mirrorNormal);
         VecMulf(vec, dist);
-        VecSubf(mirrorUp, zaxis, mirrorNormal);
+        VecSubf(mirrorUp, axis, vec);
         if (Normalize(mirrorUp) == 0.f)
         {
-            // mirror is horizontal
+            // should not happen
             THRWEXCP(MirrorHorizontal, S_OK);
             return;
         }