Matlab doesnt recognize file in path while using readObj

Answer 1

[Guillaume]

sarl = readobj(something)

Pass the content of the variable called something to the function readobj. If readobj expects a filename, the content of that something better be a file name. Of course, if you don't have a variable called something, then matlab will error with undefined variable "something".

sarl = readobj('something')   %Note the ''
%or
sarl = readobj("something")   %in R2016b or later

Pass the text something to readobj.

Two completely different things.

You meant:

sarl = readobj('butan.obj');
%or
sarl = readobj("butan.obj");