Discover how to create captivating volumetric projector effects in Blender 4.5+ using animated video textures. This tutorial by Polyfjord outlines the essential workflow for dynamic volumetric lighting, perfect for adding unique atmosphere and stylized god rays to your scenes.
Achieving truly dynamic and atmospheric scenes in 3D often hinges on mastering light. While static light setups can be beautiful, incorporating movement elevates realism and narrative quality. Expert creator Polyfjord tackles this challenge by demonstrating a powerful technique: building a volumetric projector effect in Blender 4.5 and later versions.
This method transforms a simple spotlight into a high-powered, scene-lighting asset that projects animated video textures through volumetric fog. It’s a versatile setup, ideal for generating intricate light patterns, realistic animated god rays, or dramatic cinematic effects.
Step 1: Laying the Foundation with Volumetrics
Before any light can be projected, the environment needs volume. The setup relies exclusively on the Cycles renderer, as Path Tracing is necessary for accurately rendering complex volumetric scattering.
The process begins by enabling a scene-wide volumetric fog:
1. Renderer Setup: Ensure the render engine is set to Cycles, preferably utilizing GPU compute for improved performance.
2. World Shader: Switch the Shader Editor to World mode. Delete the default Background node.
3. Volume Scatter: Add a Volume Scatter node and connect it directly to the World Output’s Volume input. To prevent the scene from becoming completely opaque, the Density must be significantly reduced, often to 0.1 or lower. This low density allows the light to scatter visibly without obscuring the scene.
Once the volumetric world is established, adding a standard Spotlight and increasing its power will immediately reveal a visible light cone cutting through the fog.
Step 2: Animating the Projection Texture
The key innovation lies in using an animated video file as the source texture for the spotlight’s emission material.
Preparing the Spotlight Material
Switch the Shader Editor view back to Object mode and select the spotlight. Make sure the Node Wrangler add-on is enabled, as it streamlines the texture setup process.
1. Quick Texture Setup: Select the default Emission shader node on the spotlight and use the shortcut Ctrl+T (thanks to Node Wrangler). This automatically adds the necessary Texture Coordinate, Mapping, and Image Texture nodes.
2. Load Video: Open the desired video file in the Image Texture node.
3. Animation Settings: To ensure the video plays in the timeline, access the N-panel (side menu) for the Image Texture node. Adjust the frame settings to match the video length and check the Auto Refresh box. The video texture is now ready to play back in real-time.
Polyfjord, known for creating incredibly useful production assets, even provides an external Animated Pattern Generator web app that can output seamlessly looping textures ready for this exact purpose.
Step 3: Mastering Technical Visual Corrections
Several critical adjustments are required to ensure the projected image looks correct and vibrant.
Aspect Ratio and Scaling
By default, the projected texture often appears squashed. Correcting the aspect ratio involves geometry and node tweaks:
1. Node Correction: In the Image Texture node, change the extension setting from Repeat to Clip. This prevents tiling and sharp edges.
2. Mapping Node: Set the scale value on the Mapping node to 2.0 and adjust the Location (often -0.5) to center the texture.
3. Object Scaling: The final step involves scaling the light object itself. In the Object Properties panel, calculate the video file’s aspect ratio (horizontal resolution / vertical resolution, e.g., 1920/1080 = 1.777) and apply that exact value to the light object’s X-axis scale.
Color Space and Denoiser
To maximize color vibrancy and prevent a washed-out look, change the Image Texture node’s Color Space from sRGB to AgX Base sRGB. This minor adjustment provides richer color representation for projection.
Finally, the complexity of volumetric projection can sometimes introduce noisy artifacts. The tutorial advises disabling the Noise Threshold for both viewport and render denoisers in the Render Properties to achieve smoother, cleaner results, especially for animated god rays.
Conclusion: Expanding Your Creative Toolkit
This technique offers more than just flat projection onto a screen; it transforms the entire scene lighting. As the creator demonstrates, objects placed within the light cone, even if not directly hit, will be illuminated by the texture’s pattern due to the volumetric scattering. This allows for truly procedural generation of dynamic lighting based on simple video inputs.
If you found this breakdown useful, Polyfjord offers the tutorial files and advanced project files via Patreon for those looking to deep dive into this powerful setup. For more advanced tutorials on complex visual effects or learning more about Lighting & Rendering in Blender, be sure to check out our extensive library of resources. You can also explore other ways to enhance your scene dynamics by visiting our VFX & Simulation category.
Source:
Tutorial: How to make a volumetric projector in Blender 4.5
