There was no mention of a unit. What does mean "when you stay in a point"?.
Images have an own category in trigger actions. For getting the camera position, there are real functions Camera - Target X/Y/Z Of Current Camera or Camera - Source X/Y/Z Of Current Camera. That being said, the maps that you have seen maybe might not have used Images but flat 3d models via units/items/destructables/effects or ubersplats and more.
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