Fix exterior light leaking into interior renders
Stop washed-out, unnaturally bright interiors by adding or unhiding a ceiling slab on the floor you are rendering, or by lowering Map Intensity and sun intensity if the open-top look is intentional.
On opening the Render dialog the app scans the active floor's visible slabs for a ceiling. If none is found and the sun (directional or ambient) intensity is above zero, it warns 'No ceiling has been added in design, exterior light might creep in.' Without a ceiling, the environment map and sun shine straight into rooms from above, producing washed-out, unnaturally bright interiors with odd shadows. Two subtleties worth knowing on a support call: (1) only the active floor is checked - a client scoped to a different floor than the one they intend to render can get a misleading warning or miss a real one; (2) a ceiling that exists but sits on a hidden layer or is toggled invisible counts as absent - both for this warning and, more importantly, for the render itself, since hidden elements are dropped from renders entirely. Fixes: add or unhide the ceiling slab on the floor being rendered, or, if the open-top look is intentional, lower Map Intensity and sun intensity so the interior is not blown out. The warning is informational only; the render fires regardless.