Math for projecting 3d world point to VR image coordinates
Your images look like being shot with an angular fisheye projection . Also, to account for epipolar geometry of stereo images, you should include the fundamental matrix into the transform engine of your geometry pipeline.
To render a 3D scene in OpenCV with a fisheye camera, one uses a fisheye camera model. Regardless of a graphics software you are using, you may find useful a description of this model's math in an OpenCV documentation.
EDIT:
When using an application like Blender, you need not construct matrices and call API methods. You just select values for dialog controls. For example, to select a fisheye lens, you do it in accord with the following ref.:
https://docs.blender.org/manual/en/2.79/render/cycles/camera.html :
CAMERA
.   Lens
.   Type : Fisheye
See also https://www.veer.tv/blog/blender-tutorial-how-to-render-a-3d-vr-video-from-blender/