a torus (doughnut) looks simple but it is a complex surface already because it is closed and has a hole....

When a model works on a torus, no doubt any Bezier surface is OK with it.

Here, I made a try on a basic Truchet pattern because I like its beauty and harmony, hoping it could be of interest to some of you to apply.

model inside. not optimized. I used CATIA XGenerative Design ( XGen for the fans...)

E01 means there is likely to be an E02 and E03 (if you allow). Feedbacks/Questions welcome 

@TB ​​​​​​​@SK ​​​​​​​ICD_HOTTOPIC