Feat/render fluids

[Just-Here-TO-Code]

Description

Improves buoyancy test containment and visuals by rendering an open-top beaker (sides + bottom only), adding invisible bottom/side colliders to prevent escape, and tinting the water a clearer blue.

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Changes Made

• renderer/window.cpp: hide the Constraints menu when world.enable_buoyancy is active.
• renderer/drawbodies.cpp: render the beaker glass as an open-top box (no top face) and keep it properly positioned above the floor.
• renderer/drawbodies.cpp: draw water as semi-transparent blue fill inside the beaker volume (with a subtle surface layer).
• renderer/drawbodies.cpp: add invisible static beaker wall colliders on the sides and a thin bottom plate so spawned bodies cannot escape sideways/downward.
• renderer/bodymenu.cpp: suppress these invisible beaker wall collider bodies in the body inspector.

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Implementation Details

• The beaker glass uses an “open-top” box mesh that omits the +Y (top) face while keeping the side and bottom faces.
• Invisible wall colliders are thin box colliders aligned to the beaker’s X/Z boundaries and a bottom plate aligned to the beaker’s bottom.
• Water fill and surface are rendered using the beaker’s inner volume dimensions, with updated blue-tinted RGBA values for clearer visibility.

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Checklist

Type:

• Bug Fix
• Feature
• Chore