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3D Room Lighting Simulator

Real-time Three.js WebGL lighting studio with live procedural human comfort and glare diagnostics.

WebGL Engine Active
Bedroom (100 lx)
3D Human Reaction
Comfort Zone: Avatar is relaxed, breathing normally with optimal visual clarity.
×
144 sq ft
800 Lumens
Comfort target rangeHarsh Glare: > 1,800 lm
2700K (Warm)
2200K 2700K 4000K 6500K
1
Optimally Lit108 lx / 100 lx target

Excellent! At 108 Lux, this lighting provides a well-balanced visual environment meeting IES recommended standards for a Bedroom.

LED Equivalent9W LED (60W Incand.)
Recommended BulbsA19 LED Soft White
Diagnostic Engine

How the 3D Avatar Reacts

Visual comfort is fundamentally about the ratio between calculated room illuminance and recommended IES standards:

  • Underlit (< 0.8x): Slouched posture, drowsy nodding head, and sleepy eyes indicating inadequate illumination eye strain.
  • Optimal (0.8x – 1.25x): Calm breathing sways, happy face, and relaxed task posture for healthy productivity.
  • Overlit / Glare (> 1.25x): Arm raised to shield eyes, head turned away, and squinted face from harsh overillumination.
Kelvin Scale

Color Temperature & Mood

Kelvin (K) ratings dictate the psychological warmth and circadian rhythm impact of your light:

  • 2200K – 2700K (Warm White): Promotes melatonin release. Perfect for bedrooms, dining rooms, and evening living spaces.
  • 3000K – 3500K (Soft White): Inviting, crisp balance. Ideal for kitchens, bathrooms, and modern living areas.
  • 4000K – 5000K (Daylight): High blue spectrum content to stimulate alertness. Best for home offices, reading desks, and utility garages.
Reflectance Factors

Why Wall Color Matters

Walls act as secondary light reflectors. Light bouncing off surfaces determines usable task illumination:

  • White / Light Paint (70%): Reflects up to 70% of light, requiring significantly fewer lumens to achieve comfortable brightness.
  • Medium Greys / Warm Tones (50%): Standard domestic baseline for balanced, soft diffuse reflection.
  • Dark / Navy / Charcoal (20%): Absorbs light heavily. You may need 1.5x to 2x more lumens or multi-fixture layered lighting.
Optical Physics & Simulation Manual

3D Photometric Simulation & Architectural Lighting Science

How real-time 3D lighting engines compute point illuminance, surface inter-reflections, Unified Glare Rating (UGR), and human circadian stimulation in architectural interiors.

1. Lambertian Cosine Law & Direct Point Illuminance

Direct illuminance received by any flat surface element (such as an office desk or dining table) from an overhead point luminaire depends on both the throw distance and the incident beam angle. According to Lambert's Cosine Law, illuminance is proportional to the cosine of the angle between the surface normal vector and the incident light ray: E = (I × cos θ) / d². When a luminaire is mounted directly perpendicular above a workstation (θ = 0°, cos θ = 1), illuminance reaches its theoretical maximum. As the luminaire moves obliquely to a 45° angle, illuminance drops by 29% purely due to geometrical spreading, even before accounting for inverse-square distance attenuation.

Point Illuminance E_direct = (Luminous Intensity I(θ) × cos θ) / Distance d²

Governed by CIE 1931 Photometry Standards. Polar luminous intensity distributions are sourced from standardized IES LM-63 and EULUMDAT digital photometric data.

2. The 80/50/20 Inter-Reflectance Cavity Benchmark

In enclosed spaces, direct light from luminaires represents only a portion of the total ambient illuminance. Photons reflect repeatedly between the ceiling, walls, and floor cavity before being absorbed. The Illuminating Engineering Society (IESNA) and CIE establish the standard baseline surface reflectance ratio: 80% for white ceilings (ρ_c = 0.80), 50% for light-tinted walls (ρ_w = 0.50), and 20% for commercial floor coverings (ρ_f = 0.20). Repainting dark walls (ρ ≈ 0.10) with high-reflectance architectural coatings (ρ ≈ 0.65) can boost effective room illuminance by up to 35% without adding a single Watt of electrical power.

Cavity Inter-reflection Factor CRF = 1 / (1 - ρ_effective × (1 - Cavity Shape Ratio))

Reflectance values (ρ): Matte White Paint: 0.80–0.88 | Light Beige / Grey: 0.50–0.60 | Natural Wood: 0.25–0.40 | Dark Carpet / Slate: 0.10–0.15.

3. Discomfort Glare Evaluation: CIE Unified Glare Rating (UGR)

Excessive luminous contrast between high-output luminaires and their background surfaces causes visual fatigue, headaches, and debilitating disability glare. The International Commission on Illumination (CIE 117-1995) quantifies discomfort glare via the Unified Glare Rating (UGR). UGR ranges on a logarithmic scale from 10 (unnoticeable) to 30 (severe visual discomfort). For continuous computer screen reading and office productivity, international standard EN 12464-1 imposes a mandatory upper threshold of UGR ≤ 19. Micro-prismatic diffusers, deep-baffle louvers, and indirect uplighting distribute lumens away from direct lines of sight.

UGR = 8 × log₁₀ [ (0.25 / L_background) × Σ ( (L_source² × ω_source) / p² ) ]

Where L is luminance in cd/m², ω is the solid angle subtended by the luminaire, and p is the Guth position index accounting for displacement from line of sight.

International Target Illuminance & Visual Comfort Standards

Recommended engineering benchmarks mapped from EN 12464-1 (Europe) and IESNA Lighting Handbook 10th Edition (North America):

Architectural SpaceTarget IlluminanceMax UGR GlareRecommended CCTStandard Reference
Living Room / Residential Lounge150 – 300 lx≤ 222700K – 3000KIESNA RP-11 / Residential
Kitchen Food Prep & Countertops500 – 750 lx≤ 193000K – 4000KEN 12464-1 Tab. 5.1
Commercial Office / Screen Reading500 lx≤ 193500K – 4000KEN 12464-1 / ISO 8995-1
Technical Drafting / CAD Stations750 – 1000 lx≤ 164000K – 5000KCIE S 008/E Standard
Classroom / Educational Lecture300 – 500 lx≤ 193500K – 4000KANSI/IES RP-3-20
Hospital Examination & Clinics1000 lx≤ 164000K – 5000KIESNA RP-29 / Healthcare
Simulation FAQs

Frequently Asked Questions on 3D Lighting Simulations

Why do simulated room lux levels differ between empty rooms and furnished rooms?

Furnishings, shelving, and partitions introduce surface occlusion (shadowing) and change the effective room cavity ratio. Additionally, furniture fabrics and wooden desks absorb light (reflectance 15–30%), reducing the overall inter-reflected flux compared to empty white-box simulations.

How does Color Temperature (Kelvin) affect circadian rhythms?

Blue-enriched daylight white (4000K–6500K) activates intrinsically photosensitive retinal ganglion cells (ipRGCs), suppressing melatonin secretion and enhancing alertness during morning hours. Warm white (2700K–3000K) minimizes blue-frequency stimulation, allowing melatonin levels to rise naturally for restorative sleep (CIE S 026:2018).

Can 3D web simulators replace commercial photometric software like DIALux or AGi32?

Our web simulator provides rapid conceptual visualization, spatial lux estimates, and interactive CCT/reflectance comparisons in real time. For certified commercial construction documentation, permit submittals, and complex emergency egress photometric calculations, engineers must employ full ray-tracing platforms such as DIALux evo or AGi32 with manufacturer-certified IES/LDT files.

What is the significance of the 200–500 lux sweet spot for human vision?

Visual acuity peaks around 300 to 500 lux for general reading and paper tasks without inducing visual fatigue. Levels below 150 lux force pupil dilation and strain ciliary eye muscles, while unshielded levels above 1000 lux can cause disability glare and reflections on digital display screens.

All 3D calculations adhere to our peer-reviewedEditorial Policyand published optical standards. Photometric values represent mathematical approximations. Please review ourEngineering Disclaimerbefore specifying commercial installations.