Setting the viewing angle and position of an image

Hi everyone!

I wish to run a 3D model on an OpenGL ES program and a Vulkan program, and wish to render the same scene and the same image with these two programs. What are some factors to consider? It’s possible that the color is slightly different, but I want to make sure the two images are the same apart from the exact colors. I am rendering on the same monitor and the same GPU, so there shouldn’t be problems with pixel sizes and such.

I have checked out camera positions, and perspective matrices, which is defined slightly differently for the two programs. I have also checked out ‘fov’ and aspect ratio, which are used in the persepctive matrix calculation, and they are the same. Is there a simple way to control the final image I render?

The images are often slightly larger or smaller than the other, due to the different zoom factors I believe, but there could also be other reasons, like slightly different rotations. Are there other influencing factors that I should take into consideration?

Wish someone could give me some hint. Thanks!

Just to close this thread and for anyone with the same problem later.
I fixed the MVP matrices and adjusted the algorithm in the vertex shader to fix the values of gl_position and other position variables.