Projection mapping is a technology that enables the display of visual content onto 3D objects using projectors. To dynamically change the projected content in response to varying real-world conditions, a projector-camera system is typically required, which combines a projector for displaying visual contents with a camera for capturing the target environment. However, estimating the geometric relationship between the projector and camera is a complex and time-consuming process, yet it is essential for accurately overlaying projection images onto real-world objects. To address this issue, a method involving the alignment of the optical axes of the projector and camera using a half-mirror has been proposed, which simplifies the alignment of their coordinate systems. However, this approach significantly reduces the intensity of the projected light, as half of the light is blocked. This research proposes a technique to pseudo-align the position and orientation of the projector and camera. Our method involves capturing two images using two cameras and synthesizing a novel viewpoint image at the optical center of the projector. This approach enables accurate projection onto 3D objects without the need for projector-camera calibration and avoids light loss during the process.