Optional Window Depth

[environ314]

Kudos on all the improvements made to the project! The amount of work looks colossal...
I appreciate all the efforts made to clarify things despite the numerous options.
What remains unclear to me is the window depth (embrasure in French).
In my naive understanding, it gets mixed up with the wall thickness.
If I understand correctly, the wall thickness affects the FOV angles. But the window depth remains a mystery. I intuitively feel that a deep window should block the light, yet you come to the opposite conclusion.

[environ314]

"Also, a small typo/mistake in the French translation:
The « Géométrie de la fenêtre » (Window geometry) menu leads to the « Géométrie du store » (Blind/Awning geometry) page."

[jrhubott]

Good question — the window depth parameter trips up most people the first time.

The key to understanding it is where the blind is mounted: the integration assumes the blind hangs at the outer wall surface. The window glass is recessed behind it.

When the sun is at an angle (gamma > 10°), it doesn't shine straight in — it comes from the side. With a deep reveal, the sun can slip past the bottom of the blind through that recessed gap, because the glass is sitting further back than the blind. To actually block that angled ray, the blind has to be lower than it would need to be for a flush-mounted window. That's the "additional horizontal offset" in the formula: depth_contribution = window_depth × sin(gamma).

Your intuition would be correct if the blind were mounted inside the reveal (between the reveal walls), because then the walls themselves would cast shadow from the side. But for an external blind, the reveal works against you at oblique angles. The deeper the embrasure, the further inward the angled sunlight effectively enters — so the blind has to extend further to compensate.

The Enhanced Geometric Accuracy wiki page has a cross-section diagram and the full effect table if you want to see the numbers.

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On the translation note: you're right that there's an inconsistency, but it exists in the English too — the nav button says "Window Geometry" while the step title inside reads "Cover Geometry." It's an inconsistency I should clean up rather than a French-specific error. I'll take a look.

For details, see the Enhanced Geometric Accuracy wiki page.