Fixed size image on semi sphere with background texture

I have a 3d model of semi sphere in .fbx format. I have to add multiple images with background texture on sphere. I am able to set the texture but not able to set image of fixed size on background. It get stretched on object surface.
Please help me how can I set the image with fixed size on sphere also would like to set the location of the image.

Can you please share an image of the current and the expected behavior? A live example would be even better.
This is the 3D model with background image. User can change the background image by selecting the background texture. Now I have to add images (any photo or text of fixed size) at Left, Right, Front, Back and Top of the Semi Sphere.
For this I divided the Sphere in five parts (Left, Right, Front, Back and Top) and able to set material for all parts. But not able to set the size, the material get implemented on complete surface of it part. If I want to set image at the center of Left Side how can I add image of fixed size at center.

I have given the link…what I have done so far…anything else you want?

If you need the texture projected in a specific way on the object’s surface, I suggest you author the texture coordinates in a DCC tool like Blender. If you correctly prepare you geometry data once, you should be able to apply textured materials in the desired way. Assuming all textures have the same properties like aspect ratio.