Project Description

ISOCE is an Image Space Occlusion Culling Engine optimized to perform occlusion culling in CPU. If you have a densely occluded scene (e.g. urban, indoor scene) you can use this module in you 3D project to speed up the rendering.

ISOCE does not depend on any Graphics API ( OpenGL, DirectX) since it is implemented in CPU and it is executed before sending the objects to the rendering pipeline.

ISOCE is DLL module programmed in C++, optimized using SSE intrinsics and is based on Hierarchical Occlusion Maps.

Overview of how it works:

  1. Select and generate the best occluders of your scene. Calculate their conservative axis aligned boxes.
  2. In every frame project the occluder´s conservative axis aligned boxes into screen space.
  3. Call ISOCE DLL module and send the occluder´s visible faces for rasterization.
  4. For every visible object you want to test for occlusion send the object´s 2D bounding box and depth. ISOCE will determine if your object is occluded or it is potentially visible.

How to use the module:

Visit Documentation page
This engine is based on the paper called: Techniques for Image Space Occlusion Culling Engine

Want to help to improve it or have any comments?

Please contact me at lebarba  at


Leandro Barbagallo  lebarba  at

Matias Leone  leonematias at

Last edited Oct 21, 2012 at 11:52 PM by lebarba, version 8