Implement Beer's Law Lighting #25

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opened 2026-01-18 14:23:24 +00:00 by akadmin · 0 comments

akadmin commented

2026-01-18 14:23:24 +00:00

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Description:
Add basic transmittance calculation using Beer's Law for cloud lighting foundation.
Tasks:

Implement Beer's Law transmittance function
Sample toward sun from each ray march step
Calculate optical depth (density accumulation)
Apply exponential attenuation
Accumulate light energy along view ray
Test with single directional light
Verify darker clouds have less light penetration

Acceptance Criteria:

Clouds darken based on density
Thicker clouds appear darker
Light attenuation looks natural
Foundation ready for phase function

Related Issues: Depends on #24
Resources:

Horizon paper lighting section
Scratchapixel Beer's Law explanation

Estimated Time: 2-3 days

Description: Add basic transmittance calculation using Beer's Law for cloud lighting foundation. Tasks: - [x] Implement Beer's Law transmittance function - [x] Sample toward sun from each ray march step - [x] Calculate optical depth (density accumulation) - [x] Apply exponential attenuation - [x] Accumulate light energy along view ray - [x] Test with single directional light - [x] Verify darker clouds have less light penetration Acceptance Criteria: Clouds darken based on density Thicker clouds appear darker Light attenuation looks natural Foundation ready for phase function Related Issues: Depends on #24 Resources: Horizon paper lighting section Scratchapixel Beer's Law explanation Estimated Time: 2-3 days