• lens

Lens bloom

By: SKY ENGINE AI
scroll down ↓to find out morelens-bloom_2_resourcesTutorial

Lens Bloom

In this case we will present you Lens Bloom postprocess step.

Agenda:

  • Lens bloom theory
  • Lens Bloom step usage

Scene setup

Let's use custom scene composer to set up the scene.
Scene consists of:

  • sphere - location: (0, 0, 0)
  • camera - location: (5, 0, 0)
  • point light - location: (2, 2, 2)
    from skyrenderer.cases.utils import LensBloomSceneComposer
    from skyrenderer.render_chain import RenderChain
    scene_composer = LensBloomSceneComposer()
    scene_composer.setup_scene()
    scene_composer.renderer_context.define_render_chain(
        RenderChain(
            render_steps=[scene_composer.visible_light_render_step],
            width=1600,
            height=900,
        ),
    )
    scene_composer.visualize()
lens-bloom_1_resourcesTutorial
2025-02-14 12:47:01,851 | skyrenderer.scene.renderer_context |  INFO: Root paths:
- root path: /home/skyengine/anaconda/lib/python3.6/site-packages/skyrenderer
- assets path: /dli/mount/assets
- config path: /home/skyengine/anaconda/lib/python3.6/site-packages/skyrenderer/config
- gpu sources path: /home/skyengine/anaconda/lib/python3.6/site-packages/skyrenderer/optix_sources/sources
- cache path: /dli/mount/cache
- ptx cache path: compiled_ptx/ptx
- ocio path: ocio_configs/aces_1.2/config.ocio

2025-02-14 12:47:04,972 | skyrenderer.utils.time_measurement |  INFO: Setup time: 3.09 seconds

2025-02-14 12:47:05,630 | skyrenderer.utils.time_measurement |  INFO: Context update time: 656 ms

2025-02-14 12:47:09,837 | skyrenderer.utils.time_measurement |  INFO: Key points calculation time: 0 ms

2025-02-14 12:47:09,838 | skyrenderer.utils.time_measurement |  INFO: Render time: 4.21 seconds

Lens Bloom theory

Lens Bloom is an optical phenomenon which manifest itself as bright flashes of light around light sources or
overexposed elements of the scene. This effect is a consequence of light diffraction on the aperture of a sensor.
In SkyRenderer it is modelled with addition of the light diffraction pattern due to the aperture of the camera and
applying it to the rendered image.

Lens Bloom step usage

We define a new render chain with two steps:

  • predefined scene composer's visible light render step
  • LensBloom postprocess step

Let's start with default parameters:

    from skyrenderer.render_chain.postprocess_steps.lens_bloom import LensBloomPostprocess
    lens_bloom = LensBloomPostprocess(scene_composer.renderer_context)
    scene_composer.renderer_context.define_render_chain(
        RenderChain(
            render_steps=[scene_composer.visible_light_render_step, lens_bloom],
            width=1600,
            height=900,
        ),
    )
    scene_composer.visualize()
lens-bloom_2_resourcesTutorial
2025-02-14 12:47:10,936 | skyrenderer.utils.time_measurement |  INFO: Setup time: 85 ms

2025-02-14 12:47:12,293 | skyrenderer.utils.time_measurement |  INFO: Context update time: 1.36 seconds

2025-02-14 12:47:16,111 | skyrenderer.utils.time_measurement |  INFO: Key points calculation time: 0 ms

2025-02-14 12:47:16,114 | skyrenderer.utils.time_measurement |  INFO: Render time: 3.82 seconds

We suggest using default values for the parameters. However, if you need a very specialized effect, you can
tweak some of them for better results. In particular, "effect_contribution" can have a major effect on
the resulting image. The higher the "effect_contribution" the more prominent the bloom effect.

    lens_bloom = LensBloomPostprocess(
        scene_composer.renderer_context,
        parameter_provider=LensBloomPostprocess.create_parameter_provider(
            scene_composer.renderer_context, effect_contribution=10
        ),
    )
    scene_composer.renderer_context.define_render_chain(
        RenderChain(
            render_steps=[scene_composer.visible_light_render_step, lens_bloom],
            width=1600,
            height=900,
        ),
    )
    scene_composer.visualize()
lens-bloom_3_resourcesTutorial
2025-02-14 12:47:17,103 | skyrenderer.utils.time_measurement |  INFO: Setup time: 67 ms

2025-02-14 12:47:17,806 | skyrenderer.utils.time_measurement |  INFO: Context update time: 701 ms

2025-02-14 12:47:19,761 | skyrenderer.utils.time_measurement |  INFO: Key points calculation time: 0 ms

2025-02-14 12:47:19,762 | skyrenderer.utils.time_measurement |  INFO: Render time: 1.96 seconds

Summary

In this section you have learnt:

  • LensBloom postprocess step must be added after visible right render step.
  • LensBloom creates light blooming effect around light sources and highly reflective surfaces.
  • The default parameters are generally recommended, but you can change them for more specialized effects.
2024-12-09_By Skyengine