greatly reduce edge lighting seam in vtHeightFieldGrid3d::ShadeDibFromElevation
greatly reduce edge lighting seam in vtHeightFieldGrid3d::ShadeDibFromElevation

nakijun/vtp,markraz/vtp,markraz/vtp,nakijun/vtp,seanisom/vtp,nakijun/vtp,nakijun/vtp,seanisom/vtp,markraz/vtp,nakijun/vtp,seanisom/vtp,seanisom/vtp,markraz/vtp,markraz/vtp,seanisom/vtp