Do You know any tool where I can "draw" a graph on torus and projective plane? (I want to draw there without intersections graphs which are not planar on R^2). I mean drawing like in Paint, not by programming (Im too weak for that).
Of course I can copy prewritten code by better people than me command to draw a torus on i. e. SageMath, but there is no way I draw a graph on it by programming.
Try chameleon.js Read the instructions, follow the link, find a torus obj file (like here), download it and drag and drop it into the browser window and start painting. You can adjust paintbrush size and color, etc.