Week 6 Light in 3D Why a «beautiful» render lies and how to fix it Light Source Types in Blender IES Profiles: The Ray Shape of a Real Fixture HDRI: Natural Light Instead of a Skybox One Camera, Three Scenarios Assignment: 3 Renders from One Camera + Fixture Specification

Week 7 Light Model 1:20 Scale and how to manage light within it Model Materials 12V Electrical Setup: Connection Diagram How to Photograph the Model on Your Phone Assignment: Model with 2 switchable scenarios + video up to 60 seconds

Cycles — the Blender engine that calculates light physically: reflections, shadows, scattering. IES — a manufacturer’s file containing the light beam shape of a fixture. HDRI — a 360° panorama with real sky and sun luminance; it illuminates the scene. Blackbody — a Blender node that sets the light color in kelvins. Strength — the source brightness in Blender, measured in watts. White Balance — a camera setting that determines whether the light in the photo will appear warm or cool.

If you place a «simple lightbulb» in a scene and adjust the brightness by eye, you can make it look beautiful, but you won’t find light like that in real life. A truthful render is built from real data: we take a fixture from a catalog, its IES file, lumens, and Kelvin rating—and import it into the scene.

Render in the Cycles engine. Eevee is faster, but its lighting is approximate.

In Blender, there are 4 types of lights. Each resembles a class of real-life fixtures.Point Bare bulb: shines in all directions. Suitable for wall sconces or lamps in a lampshade.Spot A cone of light with an adjustable angle. These are spotlights and downlights.Area A luminous surface, creating soft shadows. These include panels, light ceilings, and windows.Sun Parallel rays without attenuation. This simulates the sun.

In real light fixtures, the beam pattern varies—narrow, medium, wide, with sharp or soft edges. The manufacturer records this shape in an IES file, which can be downloaded from the website alongside the fixture’s specifications.

How to import IES in Blender01. Add a Point light source. 02. Object Data → Use Nodes. 03. Add an IES Texture node and select the file. 04. Set the power in Strength, and use the Blackbody node with the Kelvin temperature from the datasheet in Color.

Strength in Blender isn’t about the power rating. Adjust it so that the brightness ratios match your storyboard: a 900 lm light source should be roughly twice as bright as a 450 lm one.

HDRI—a panorama that illuminates the scene like a real sky: with the correct sun brightness and cloud color. For a daytime scene, this is faster and more authentic than using Sun + Area in windows.

1. Download HDRI from Poly Haven—it’s free.
2. World → Color → Environment Texture.
3. Open the .hdr file and rotate the panorama so the sun hits the window.

To compare scenarios, everything else must remain the same.

1. Lock the camera and do not move it.
2. Lock the exposure and View Transform (AgX).
3. Each scenario should be its own View Layer or a copy of the fixture collection.
4. Change only the lighting.

If the scene looks too dark, do not raise the exposure. This means there is insufficient light in the project, and this needs to be corrected within the light fixtures themselves.