In this lesson, you will learn how to combine view-dependent Fresnel mathematics with scrolling textures to craft a convincing, interactive holographic interface.
The Fresnel Effect as a View-Dependency
The Fresnel effect is the core of any hologram. In physics, it describes how the reflectivity of a surface changes based on the viewing angle. In Shader Graph, we calculate this using the Fresnel Effect node, which returns a value of 1.0 when the surface normal faces away from the camera and 0.0 when it faces directly toward it. By using this as an Alpha or Emission mask, we ensure the "glow" of our hologram is strongest at the edges, perfectly mimicking the way light interference behaves on projected sci-fi displays.
Integrating Scanline Textures
A static hologram feels flat. To breathe life into the material, we introduce a scanline texture. By plugging a Time node into a Tiling and Offset node, we can shift the UV coordinates of a horizontal stripe texture over the surface.
To blend this with our Fresnel effect, we use a Multiply node:
- Fresnel Effect: Defines the silhouette glow.
- Scanline Texture: Provides the vertical data-processing movement.
- Combination: By multiplying these, the scanlines only appear where the Fresnel intensity is high, or conversely, use the scanlines to mask the Fresnel to create "broken" holographic strips.
Implementation Logic
When setting up your Master Node, ensure your surface type is set to Transparent. Your logic should flow as follows:
// Conceptual Shader Graph structure
Fresnel (Power: 3.0) * Scanline_Texture (Time-offset UV) = Final_Emission
Fresnel (Power: 1.5) * Alpha_Constant = Final_Alpha
Adjusting the Power input on the Fresnel node is crucial; lower values (e.g., 0.5 to 2.0) create a broad, soft glow, while higher values (e.g., 5.0+) produce a razor-thin, sharp rim light. Because we are working with transparency, remember to keep your emissive color values high (HDR) to trigger the Bloom post-processing effect, which is the final "polishing" step for that iconic sci-fi look.
Key Takeaway: The Fresnel effect provides the spatial "rim" for the hologram, while time-offset scanline textures provide the temporal movement, together creating a depth-rich, interactive UI surface.