hello,
first I would ask you from where comes this obj ? I mean what app ?
Because there is Goz wich help you to export/import your model with it textures right into zbrush without moving a finger;
but it let me presume that it is a downloaded model (third part).
Anyway,
if you import an obj manualy, you will (usually) have to import manualy its textures.
So after you have imported the obj model and it appears without texture,
go to texture MENU and then clic on 'import (^^)
go to 'Texture from Tool PALETTE and clic on the empty square, then choose the just imported texture
note that you have sometimes to flip V (from Texture menu), so it fixes bad orientation
if you want to ‘tweak’ this polypaint into zBrush, directly on your model, then go to ‘polypaint’ from tool palette, and clic on 'polypaint from texture
ps: I think nothing is ‘simple’ when you are trying to learn, especially with 3d. only youtube vidz/tuts looks like all is simple, but the reality is not. Because before they made their tutorials, they had to learn & to understand what is going on.
This gives me opportunity to give you maybe the best advice I can;
when you search something with Google for instance (learning 3d), if you don’ t find what you were looking for, it must & should mean that you have not search enough…
…I know it does not sound good and maybe it is harsh, but unfortunatly or not, it is usually the case. The faster you admit it,
the faster you will solve the problems you encounter, alone, without posting for help, and waiting somebody gives you help (simple or not).
For me,
this is one of the main key to learn 3d ‘alone’, and the more you spend time on searching infos, documentations, tutos, the more you will be able to find what you were looking for. and then you will be able to search faster, more effective, with appropriate or relevant terms, etc
Notice that internet is all what humanity has done or is doing, in term of knowledge. So all is there, it is just a matter of searching, time of searching, and ways of searching (method, terms, etc).
I am sorry if I am not clear or if I give you harsh reply, but I think it is the best I can do for you, and for all beginners (in all sort of matters), instead of only give you the reply you were waiting for (texture import).
What I can say else is that the best source of informations about an application, is to go to its original native official website, like zbrush:
there are dedicated official documentations, classroom, etc… even before youtube because youtube can make you think that all is simple (I personaly think that nothing is simple unless you have 'studie it, understand it, practice it, etc)
all have a shortcut that can avoid you to learn, search, think, etc but it is direct path to disapointment, and inefficiency.
ps: don’ t hesitate if I am not clear or if if you have another question.
ps(2): I have tested this terms on Google:
zbrush apply texture on imported obj
Gave me the first link a tutorial of more than 30mn that explain basics, so maybe it will help you I don’ t know. And it is HD