Renderer Module — Mesh Craft Docs

Components

Class	File	Role
`SceneRenderer`	`src/MeshCraft/Renderer/SceneRenderer.cpp`	Renders all MC3 objects, transform gizmos, light/camera icons, edge overlay, and CSG booleans.
`GridRenderer`	`src/MeshCraft/Renderer/GridRenderer.cpp`	Draws the infinite XYZ reference grid using CNA `BasicEffect` and a `VertexBuffer`.

SceneRenderer Overview

SceneRenderer is initialized once in LoadContent(). During initialization it builds all pre-computed unit meshes (a 1×1×1 box, unit sphere, unit cylinder, unit cone, unit plane) as VertexBuffer + IndexBuffer pairs. Each mesh is stored in a RenderMesh struct that holds:

A VertexPositionColor VB+IB pair for flat-colored rendering
A VertexPositionNormalTexture VB+IB pair for lit+textured rendering
A WireShape for edge overlay (line-list geometry)

Each frame, SceneRenderer::draw() is called with the Mc3Document, view and projection matrices, and the current selection list.

Draw Traversal

The renderer traverses the scene graph recursively via drawObject():

Compute world matrix from Mc3Transform using the pivot-compensated formula:
world = T(pos + pivot) × R(rotation) × S(scale) × T(-pivot)
Apply animation overrides — if an animation clip is playing, the animOverrides_ map may replace the transform position/rotation/scale and visibility for this object.
Select render path by ObjectType:
- Box/Cube → scaled unit box
- Sphere → scaled unit sphere
- Cylinder → scaled unit cylinder
- Cone → scaled unit cone
- Plane → scaled unit plane
- Extrude → dynamically tessellated sweep mesh (per-frame, cached)
- Mesh → OBJ loaded via tinyobjloader (loadOrGetMesh(), cached by path)
- Group → render children recursively
- Instance → resolve definition, render with overridden material
- Union/Difference/Intersection → evaluate Manifold CSG, cache result
- Area → (no visual representation)
Look up material: if the object has a material ID, retrieve Mc3Material.baseColor from the document map. If the material has a baseColorTexture, load/cache the texture.
Render via drawMesh() (flat color) or drawMeshTextured() (texture).
Wireframe highlight: if the object is selected, draw a white wire box around its AABB.

Key Data Structures

struct RenderMesh {
    unique_ptr<VertexBuffer> vb;    // VertexPositionColor
    unique_ptr<IndexBuffer>  ib;
    unique_ptr<VertexBuffer> texVB; // VertexPositionNormalTexture
    unique_ptr<IndexBuffer>  texIB;
    int primitiveCount, texPrimitiveCount;
    vector<Vector3> positions; // for AABB picking
};

struct AnimOverride {
    optional<array<float,3>> position;
    optional<array<float,3>> rotation;
    optional<array<float,3>> scale;
    optional<bool>           visible;
};

Caches

Cache field	Key	Invalidated by
`textureCache_`	Absolute file path	Never cleared (textures are immutable in the current session)
`meshCache_`	Absolute OBJ file path	Never cleared
`csgMeshCache_`	`const Mc3Object*`	`clearCsgCache()` — called from `pushUndo()` on every document mutation

Animation Overrides

Before each draw() call, MeshCraftApplication::evaluateAndPushAnimOverrides() evaluates all channels of the currently playing action at the current time, building an unordered_map<string, AnimOverride> keyed by object name. This is then injected into the renderer via SceneRenderer::setAnimOverrides().

GridRenderer

Draws a flat reference grid in the XZ plane centered at the origin, plus colored X (red), Y (green), and Z (blue) axis lines. Uses CNA's BasicEffect with vertex color enabled. The grid vertex buffer is built once and reused each frame.

Editor Scene Panels