Java-leven

Dual Contouring Chunking LODs with seams

This solution based on Nick Gildea Dual Contouring https://github.com/nickgildea/leven This is Java LWJGL implementation

This project is written in Java. Created for the practice of Java core. The code will be very clear to Unity users.

CPU and OpenCL GPU implementations.

Improvements relative to the original solution

• fixed the appearance of holes in the seams between chunks
• fixed seam and chunk mesh overlap at seam intersections
• no double call to generate mesh for rendering and mesh for collisions - mesh is generated only once
• faster selectActiveChunkNodes and ReleaseInvalidatedNodes (no need to recursively traverse the whole tree to invalidate chunks - which improved performance)
• Linear chunk's octree instead of Pointer Based octree. It used Morton codes.
• Chunks reduce instead of queue of CSG operations. Only the leaf chunk is edited. Rougher chunks have a simplification of the voxel lattice with Hermite data.
• The main version is on the CPU. I use multithreading to speed up the CPU version

In first run it generate density field and store it to file. For this reason, the first time the demo starts for a long time

Features:

• Used JBullet physics engine (ray pick and collision detection);
• Many octree Dual contouring implementations:
  Pointer based octree Dual contouring implementation,
  Linear octree Dual contouring implementations:
  
  • Simple implementation, in series steps to calculate leafs data.
  • Nick Gildea Leven Dual contouring implementation translated to Java CPU realization - LevenLinearCPUOctreeImpl.java
  • Nick Gildea Leven OpenCL Dual contouring implementation. In this implementation LevenLinearGPUOctreeImpl.java I call OpenCL kernels in java .
• CSG operations (add/delete sphere/box brushes);

Video https://www.youtube.com/watch?v=ewr7YZyBYnI

CSG operations:

## Build Instructions please, perform
mvn clean install

The dependencies are:

• Maven
• Java 11
• I used IntelliJ IDEA Community edition
  
  

W/S/A/D - forward, backward, left, right

Tab - enable/disable mouse rotation mode

R_Mouse - perform CSG brush to object

R - switch CSG brush / sphere / cube

M - switch CSG operation (add/delete mode)

[ - increase brush size

] - decrease brush size

F1 - solid / wireframe

F2 - Show chunks octree bounds

F3 - enable / disable frustum culling

F4 - show bounds of the seam octree nodes

middle mouse with mouse move - camera walking (without change direction of movement)

right mouse - ray pick from mouse cursor to intersection point with landscape

arrows - change camera direction (with change direction of movement)

Use:

JBullet - I use my modified version of JBullet https://github.com/proton2/jbullet

Oreon Engine (Java - OpenGL/Vulkan) https://github.com/fynnfluegge/oreon-engine

interesting for research:

• Nick Gildea Dual Contouring https://github.com/nickgildea/leven

• Dual contouring chunks
  https://github.com/yixinxie/TestDC/

• Dual contouring by SVD https://github.com/S-V/DualContouringTest

• SVD dissertation https://www.vstu.ru/upload/iblock/d6b/d6b39e94a85205ec02495af30f94605e.pdf