Feat/upgrade and bug fix

[sudhir9297]

What does this PR do?

This PR introduces a mix of UX improvements, duplication workflows, geometry fixes, walkthrough (first-person) functionality, and rendering corrections across multiple editor systems.

It focuses on:

• Improving material editing consistency and paint-mode behavior
• Adding duplication workflows for floor plans and levels
• Fixing placement, snapping, and geometry issues
• Introducing a full first-person walkthrough system with collision
• Enhancing spawn point handling and visuals
• Improving door rendering logic and walkthrough collisions

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Material & Paint UX

• Standardized custom material controls in paint-panel.tsx:
  • Reused the same slider component pattern for:
    • Roughness
    • Metalness
    • Opacity
• Hid wall-building shortcut helper while material paint mode is active:
  • Prevents tool hint overlay from appearing during paint mode

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Placement & Snapping Fixes

• Fixed ceiling-attached item placement after moving floors/levels:
  • Switched to ceiling-local coordinates for snapping and preview alignment

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Floor Plan & Level Duplication

• Added floor plan duplication support in site panel:

  • Creates a copy with same settings
  • Applies slight offset to avoid overlap

• Added level duplication in:

  • Level actions menu
  • Floating level selector menu

• Implemented subtree cloning:

  • Duplicates full level and its contents
  • Automatically selects duplicated level

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Level Duplication Options

• Added "Duplicate with options..." flow
• Shared duplication logic across menus
• Implemented duplication presets:
  • Everything
  • Structure only
  • Structure + materials
  • Structure + furniture

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Stair Opening & Geometry Improvements

• Reworked curved stair auto-opening generation:

  • Based on actual stair rise and target surface elevation
  • No longer relies on fixed arc slices

• Extracted reusable helpers:

  • Step count calculation
  • Arc opening polygon generation

• Updated curved stair cutouts:

  • Respond to actual target elevation (slabs/ceilings)

• Improved opening coverage:

  • Increased default opening ratio
  • Added step padding so openings start earlier

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Door Rendering Fixes

• Fixed door segment rendering:
  • Selecting "Empty" no longer renders a solid panel
• Stopped rendering internal dividers for empty segments
• Added guard:
  • If all segments are empty → hide:
    • Leaf border trim
    • Handle
    • Door closer
    • Panic bar
    • Hinges
• Updated door schema to define "empty" as no leaf fill

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First-Person Walkthrough

• Replaced previous walkthrough with a new custom first-person controller
• Added BVH-based collision system
• Implemented:
  • Gravity
  • Jump
  • Sprint
  • Slope handling
  • Collision response
• Disabled editor camera controls during walkthrough
• Added pointer-lock with Esc exit handling
• Fixed keyboard conflicts so movement keys don’t trigger editor shortcuts
• Restored active floor automatically after exit
• Hid spawn marker while in walkthrough
• Fixed start position to use spawn’s real world transform

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Spawn Point System

• Introduced a dedicated Spawn Point scene node

• Added spawn to Build tools for direct placement

• Integrated spawn into:

  • Scene graph
  • Selection system
  • Property panel

• Updated behavior:

  • Live rotation updates during interaction
  • Correct placement using level-local coordinates
  • Singleton pattern (only one spawn per project)
  • Reusing spawn moves it instead of duplicating

• First-person mode always starts from this spawn point

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Spawn Marker Visuals

• Replaced previous figure with simplified block-style marker
• Built custom marker with:
  • Body
  • Head
  • Ring
  • Direction indicator
• Unified materials and colors
• Memoized shared materials for performance
• Tuned placement and rotation of marker components
• Hid player capsule preview while keeping selection active

---

Collision & Walkthrough Fixes

• Built collider world from scene registry
• Excluded non-collision helper meshes
• Fixed collider hierarchy issues:
  • Prevented parent nodes from re-including child colliders
• Updated door collision:
  • Empty or fully empty doors no longer block movement

---

Walkthrough UI

• Added first-person overlay UI:
  • Crosshair
  • Exit button
  • Movement hints
• Fixed crosshair alignment
• Moved help panel to right-side vertical layout
• Improved readability of controls (Jump/Sprint)

---

Editor & Toolbar Polish

• Updated Build tab spawn icon:
  • Replaced custom icon with standard generic icon