Attempts to optimize the game by making item frames render with 1 shape instead of 5. Making the frame of the item frame flat with the middle part instead of extruded outwards.
If you are here for performance improvements, combine this with ImmediatelyFast
Also check out my other resourcepack: Unexplored Map Highlighter
Without Simple Item Frames: !Picture showing item frames types, with wooden frame extruded up With Simple Item Frames: !Picture showing item frames types, with wooden frame flat with middle part
Original by u/RandomIntel: https://www.reddit.com/r/Minecraft/comments/5x3im6/i_updated_simple_item_frames_for_all_the_versions/
Updated to 1.16.4 by u/hazzeFox: https://www.reddit.com/r/Minecraft/comments/lhfagg/i_updated_randomintels_simple_item_frames/
Updated to 1.21.4 by me (Cobwebblocks): Adds glow item frame and changes resource pack version to match game version