This tutorial will guide you through the process of setting up the light source, adding volumetrics, and fine-tuning the scene to achieve an effect known as “God Rays”.
Step 1: Set Up Your Scene
Launch Blender and open a new or existing scene where you want to create God Rays.
You can download this simple isometric room from Fab. The link is in the description.
Add an Area Light. Position the light so that it will be shining through the window. Increase the Size of the Area Light and the Power in the Data tab. [10,20000]
In Blender, the volumetric lighting effect is controlled through the World Settings and Render Properties.
Go to the Render Properties tab and enable Cycles as the render engine (God Rays work best with Cycles due to its ability to handle volumetric effects).
Step 2: Add a Volume Cube for Control
To shape the volume and contain the God Rays, add a Cube and scale it to fill the room. This will act as the dust particles which are needed for the effect.
To see the room interior, open the Object tab. Under the Viewport Display, change the ‘Display As’ to ‘Wire’. This will allow you to see the interior of the room while also maintain the volume container.
Switch to the Render View and name your objects in the Outliner.
Select the cube and open the Material tab. Create a new Material for it.
Delete the Principled BSDF shader.
Under the Volume Panel, add a Principled Volume shader to the cube’s material.
In the Principled Volume shader, adjust the Density value to control the intensity of the fog or atmosphere.
A value of around 0.1 will give you a decent starting point. You can tweak this later to get the exact amount of fog and intensity.
Step 3: Adjusting the Volumetrics
You now have the basic setup for the God Rays. However, some adjustments still need to be made.
Select the Area Light and open the Light tab. Change the ‘Max Bounces’ to zero. This forces the light to illuminate the light path and not the rest of the room.
Step 4: Fine-Tuning the God Rays Effect
The angle of the camera and the amount of light coming through the scene will affect how visible the rays are. To make the rays more visible, position the camera so that you are looking toward the light source.
You may want to use the Depth of Field settings in the Camera to blur the background slightly, making the God Rays stand out even more.
Select the Camera and open the Camera tab. Activate the ‘Depth of Field’. The quickest way to use Depth of Field is to use ‘Focus on Object’. In this case, you can choose the window as the Object.
Experiment with the Density and Color of the volume to fine-tune the visibility of the God Rays.
Increasing the Density will make the rays more pronounced, but be careful not to make the scene look too foggy.
The color and strength of the light also play a big role in making the God Rays look more natural. Play with the light’s color and intensity to get the look you want.
For realistic results, use a slightly yellow or orange light to simulate sunlight.
Step 5: Final Render and Post-Processing
Use NumPad Zero to view the scene through the Camera. Set up the scene as desired.
Set your render resolution and make sure samples are high enough to avoid noise (around 1000 samples should work well for high-quality volumetric effects).
Under the Render menu, you are now ready to render the image.
Conclusion
Congratulations! You’ve successfully created God Rays in Blender using volumetric lighting, lights, and clever use of shaders. These rays can add a lot of atmosphere and drama to your scenes, whether you’re working on landscapes, interiors, or any other 3D project.