So .. after some testing and timing I''ve decided on using large 192x192 square tiles for my ground plane and smaller tiles for my objects. An ''unit square'' in my coordinate system is 32 x 32 pixels, so that''s 64 x 32 pixels in iso coordinates. Therefore I store my current view or world coordinates and simply devide by 32 in each axis to get my map index location from the top left. I know I could do this all using 3d coordinates and not use a map[][] array but I have lots of data that needs to be stored in specific 32 x 32 point locations so its the best to do.. To speed things up I draw the ground as huge squares that have isometric drawings on them but arn''t diamond shapes. This works great and all, but I am having a hard time figuring out how to use my world coordinates to figure out which SQUARE tile I should be displaying. I need to be able to look into the appropriate index location and draw the square ground plane tile in the right place. Has anyone tried doing this or does anyone have any ideas?