The interactions between hallucinations and reality in people with schizophrenia A person with schizophrenia sees a door become open, while in reality it's closed. What would he see when he tries to pass through the door? 


Bumps into an invisible obstacle.
He sees the door become closed just before he tries to pass.
He opens the door himself just before passing through it, but his brain meticulously ignores his action or alters his memory so that he thinks the door was already open.
Unfortunately hallucinations of visual type seldom occur with schizophrenia. When visual hallucinations occur in schizophrenia or more frequently (but still uncommon) in other disorders they are rather unlike a simulation of the current world - e.g. a closed door becoming open in the room. In addition patient in a hallucinatory state is very affectively taken by the experience and often is just afraid to move. Further - the only way to know would be to ask the patient as to what happened, but given that this kind of event is very rarely, if at all, happening, there is no answer because - how can you set up an experiment. Therefore this question, interesting though it may be, is just of speculative value.

A good article about the topic is:  

M Manford  F Andermann, Complex visual hallucinations. Clinical and neurobiological insights. Brain, Volume 121, Issue 10, 1 October 1998, Pages 1819–1840