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global_illumination

luboslenco edited this page Jun 30, 2019 · 3 revisions

Global Illumination

This page presents a quick start guide to let you easily setup global illumination in your Armory projects.

Armory features a fully dynamic global illumination technique based on a combination of voxel cone-tracing and screen-space ray-tracing. First, the scene is voxelized and processed into a 3D texture. This data is then used to gather coarse lighting of the scene. Afterwards, screen-space ray-tracing is performed for detail.

Requirements

  • A graphics card with OpenGL 4.4 or Direct3D 11 support (for voxelization).
  • Runs on Windows and Linux.

Voxel AO

Set Armory Render Path - Voxels - Global Illumination to Voxel AO.

The cheapest way of utilizing voxels, usable for ambient occlusion and shadows. Runs faster and consumes less memory compared to Voxel GI.

  • Control the quality using the Cones property.
  • Control the intensity using the Occlusion property.
  • Tweak tracing parameters using the Step, Range, Offset properties.
![](graphics/img/gi/ao.jpg)

Voxel GI

Set Armory Render Path - Voxels - Global Illumination to Voxel GI.

Voxel GI enables indirect diffuse and specular lighting. This is a performance heavy feature and should be enabled only on higher-end hardware. Flickering or leaks can occur.

  • Control the quality using the Cones property.
  • Control the intensity using the Diffuse, Specular, Occlusion properties.
  • Tweak tracing parameters using the Step, Range, Offset properties.
  • Control environment map contribution to indirect lighting using Env Map property.
![](graphics/img/gi/game.jpg)

Voxel Volume Setup

Locate Armory Render Path - Voxels panel. When set to Voxel AO or Voxel GI, voxelization volume can be configured.

  • Adjust Dimensions to control the volume size. Objects placed out of this volume will not contribute to global illumination. By default, dimensions are set to 16 - meaning a volume of 16x16x16 blender units gets voxelized.
  • Set Resolution to specify amount of voxels used for the volume. For performance, keep this at 128 or below.
  • Reduce the Resolution Z multiplier to conserve memory if your scene is mostly flat on the Z axis (like a chess board). With Resolution Z set to 0.5, 16x16x8 dimensions will get voxelized.
  • Enable Revoxelize property to update voxel volume every frame. In case of mostly static scenes, you can keep this off - moving objects will receive indirect lighting, but will not affect it. To prevent object from contributing into indirect lighting, enable Properties - Object - Armory Props - Mobile.
  • With Revoxelize checked, enable Dynamic Camera to voxelize scene around the camera. As the camera moves, voxelization volume will move as well, making it possible to cover infinitely big scenes. With Dynamic Camera disabled, the volume at the scene origin(0,0,0) gets voxelized.
  • Relight property will allow the voxel volume to be recomputed when light transform changes.
  • Temporal Filter will blend the indirect lighting with results from the previous frame, in order to minimize flickering.

Screen-space ray-tracing

Ray-traced AO

Set Armory Render Path - SSGI to RTAO.

Ambient occlusion will be traced.

  • Control the quality using the Rays, Step, Max Steps properties.
  • Control the intensity using the Strength property.

Ray-traced GI

Set Armory Render Path - SSGI to RTGI.

Indirect diffuse lighting will be traced.

  • Control the quality using the Rays, Step, Max Steps properties.
  • Control the intensity using the Strength property.

Ray-traced Shadows

Small scale contact shadows will be traced.

Enable Armory Render Path - SSRS.

  • Increase Step in case of artefacts.

Ray-traced Reflections

Local reflections will be traced.

Enable Armory Render Path - SSR.

  • Increase Step in case of artefacts.

Baked lighting

Blender has a full path-tracing Cycles engine integrated. For static scenes, you can pre-bake lighting down into lightmaps using the built-in Armory Bake tool.

  • Locate Properties - Render - Armory Bake panel.

  • Add objects to be baked or click Triangle - Add All.

  • Hit Bake to generate lightmaps for all listed objects.

  • Once done, hit Apply to restore materials and pack lightmaps.

  • Optionally, set Armory Render Path - Preset to 2D/Baked.

  • Run(F5)! Armory picks up baked materials.

  • Get example .blend scene.

Light probes

Currently supported light probe features:

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