Is there anyway to increase the rendering resolution? The game still looks likes it's 640x480 even the the window is my monitor's native.

I'm afraid that is the best resolution you will get since these games are quite old, so that leaves you with the HD mods, try seamless or rebirth, I think those would be your best options possible right now...

Ok, so I went to explore the game on gog galaxy, and here it is what you can do:

1.- Open gog galaxy
2.- go to owned games and select your resident evil game
3.- on the top of the options (overview, My progress, extras.etc.) go to the button options in the far right and click on it to open the submenu.
4.- select the first option "additional executables" and select the only one "DirectX settings".
5.- A new window will open, on there go to the display mode and select "Same as desktop (default)" or select your favorite resolution.
6.- Then click on save and exit the setup.
7.- Try and play the game and see if that satisfy your needs, in case you want far more better graphics, you will have to try the HD mods...

There are other options on there you can try to customize your experience but if you dont like them, you will have to try the mods...

You have to go into the files and select your resolution in the dxcfg.exe. For some reason "same as desktop " isnt actually the same as desktop and the models appear quite pixely so just go in and select your actual resolution in that program and they then appear mucgh smoother.. Res 2 and 3 have a little launcher where you can open the video settings from there before starting the game but Res1 doesnt have that.

F1 in-game let's you change the game resolution