"My room is opened."

Translation: Kamar saya terbuka.

[Origin5world5_]

Isn't di- used to say that someone made it so, and ter- used to just describe an observation, it is just like that?

So "jendela dibuka" would mean: the window is opened.

As for "jendela terbuka" it would mean: the window is open.

[Diponegoro57]

Yes!
So, "Botol ini diisi (dengan) teh (oleh Tini)." describes the action of the bottle having been filled with tea.
Whereas, "Botol ini terisi (dengan) teh." describes the state of the bottle as being filled with tea.
I think that we were given these examples earlier, but I am not sure if "dengan" is needed in each, though doubtless in spoken BI it can be skipped without loss of meaning!

[Chris269076]

I agree. "ter-" is not concerned with how the window got to that state. "di-" implies an agent, ie., "by someone", by Fred", "by the wind". Works for me!

[Jake929031]

I feel dibuka is more correct.

[leeyongqian]

What's the difference between kamar and bilik?

[Alex316039]

What is the difference between terbuka and dibuka?