Tucil2_13524017_13524081

3D Object Voxelization using Octree

A program that converts 3D models (.obj) into voxelized representations composed of small uniform cubes, similar to Minecraft. The conversion is performed using an Octree data structure with a Divide and Conquer algorithm. Only the surface of the object is voxelized, and voxel collection is done concurrently using Java's ForkJoinPool for improved performance.

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Requirements

• Java Development Kit (JDK) 17 or higher
• No external libraries required

To check your Java version:

java -version

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Compilation

From the root directory of the repository, run:

javac -d bin src/*.java

This will compile all source files and place the compiled .class files into the bin/ directory.

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How to Run

After compiling, run the program with:

java -cp bin Main

The program will prompt you interactively:

=================================================
     Voxelization Objek 3D menggunakan Octree    
=================================================
Masukkan path file .obj : test/input/pumpkin.obj
Masukkan max depth      : 5

• Path file: Enter the path to the .obj file, either relative or absolute (e.g. test/input/bunny.obj or C:\models\bunny.obj).
• Max depth: Enter a positive integer representing the maximum depth of the octree. Higher depth = more detailed voxelization but longer execution time.

The voxelized output .obj file will be saved to test/output/. Additional .obj files for testing and experimentation are provided via an external Google Drive you can access here : https://drive.google.com/drive/u/0/folders/1KClZsiCBkkNUVR8IZ7QVc3_Md8761h96

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Program Output

After running, the program will display:

• Number of voxels, vertices, and faces generated
• Octree node statistics per depth (including root at depth 0)
• Pruned node statistics per depth
• Total execution time (parse + octree build + voxel collection)
• Output file path

Example output:

=================================================
              HASIL VOXELISASI
=================================================

  Jumlah voxel   : 10896
  Jumlah vertex  : 87168
  Jumlah face    : 130752
  Kedalaman max  : 6

  Statistik Node Octree (node terbentuk per depth)
  0 : 1
  1 : 8
  2 : 64
  3 : 160
  4 : 704
  5 : 2656
  6 : 10896

  Statistik Node yang Tidak Ditelusuri (pruned per depth)
  2 : 44
  3 : 72
  4 : 372
  5 : 1294

  Kedalaman octree    : 6
  Waktu eksekusi      : 309 ms
  Path file output    : test/output/cowres.obj

=================================================

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3D Viewer (Bonus)

After voxelization completes, the program will ask if you want to open the result in a 3D viewer:

Buka 3D viewer? [y/N]:

The viewer is built from scratch using javax.swing and java.awt with manual implementation of:

• Camera representation
• Perspective projection (3D → 2D)
• Screen space mapping
• Back-face culling
• Painter's algorithm

Controls:

• Left drag: Rotate model
• Scroll: Zoom in / out

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Repository Structure

Tucil2_13524017_13524081/
├── src/
│   ├── Parser.java       # OBJ file parser and validator
│   ├── BoundingBox.java  # AABB with SAT triangle intersection
│   ├── Octree.java       # Octree build with Divide and Conquer
│   ├── Voxel.java        # Voxel collection (concurrent ForkJoin)
│   ├── ObjWriter.java    # Write voxelized OBJ output
│   ├── Output.java       # Statistics and report
│   ├── Viewer.java       # 3D viewer (bonus)
│   └── Main.java         # Entry point
├── bin/                  # Compiled .class files (not tracked)
├── test/
│   └── input/            # Sample OBJ files for testing
├── doc/                  # Laporan PDF
└── README.md

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Author

Name	NIM
Aziza Dharma Putri	13524017
Alya Nur Rahmah	13524081

Program Studi Teknik Informatika
Sekolah Teknik Elektro dan Informatika
Institut Teknologi Bandung
2025/2026