node_pool_builder.mdx

Overview

The node_pool_builder class is an extension of node_pool that constructs voxelized spatial hierarchies (SVDAGs) from 3D scene geometry. It converts input geometry into a voxel DAG structure by recursively subdividing space, useful for real-time rendering, compression, and level-of-detail systems.

Note: This feature requires Assimp and is only available when ASSIMP_SCENE_ENABLED is defined.

Requirements

  • Assimp scene loader must be enabled.
  • glm must be available for 3D vector math.

Class: node_pool_builder

Inherits

class node_pool_builder : public virtual node_pool

Description

Builds a node_pool from a scene using recursive spatial subdivision. The voxel structure is stored in the node_pool base.

Public Interface

Constructor

explicit node_pool_builder() = default;

Initializes a new builder instance.

void build(scene* p_scene, int depth, glm::vec3 corner, float size)

Builds a node pool from a 3D scene.

Parameters

  • p_scene: Pointer to the scene containing geometry.
  • depth: Octree depth (higher values increase resolution).
  • corner: The minimum corner of the bounding volume.
  • size: Length of the bounding cube's edge.

Notes

  • This method is unoptimized and meant for initial experiments or small-scale data.

Private Method

int recursive_build(...)

Internal recursive function that subdivides space and deduplicates nodes.

Parameters

  • p_scene: Scene pointer.
  • d: Current depth.
  • md: Max depth.
  • min: Minimum corner of current volume.
  • size: Edge length.
  • indexes: List of current voxel indices.
  • start: Starting index in indexes.
  • dedup: Hash map for deduplication (node_t<int> → int).
  • progress_callback: Function to track progress.

Returns

  • Index to the node pool after processing the region.

Notes

  • Use compress() afterward to reduce redundant nodes.
  • Consider optimizing this for production by batching or GPU acceleration.

Related

  • node_pool
  • [scene](Assimp-compatible abstraction)