Contents
Image Parallax simulates complex 3D surface depth on flat geometry using advanced Parallax Occlusion Mapping (POM). Unlike standard Bump or Normal mapping which only affects lighting, this node calculates actual self-occlusion and parallax shifts by ray-marching through a virtual height volume. It creates the illusion of deep cracks, bricks, and displacement without the heavy cost of tessellating geometry.
Usage & Behavior
This node is designed to act as a "Pre-Processor" for your material. You plug your Height Map into it, and it outputs Shifted/Parallaxed UVs. You then use these new UVs to sample your Base Color, Roughness, etc. This ensures that the texture "sinks" into the holes correctly. It also outputs a calculated Normal and Occlusion map based on the ray-traced depth. However you can also use a diffuse/albedo texture directly and grab the parallaxed output wih the Color socket.
Key Features
- Parallax Occlusion: Full ray-marching with Binary Search refinement for high precision.
- Self-Shadowing: Calculates ambient occlusion shadows cast by the height map peaks.
- Smart Filtering: Intelligently suppresses noise on flat surfaces while preserving deep edges.
Deep Dive: The "Brick vs. Mortar" Problem
Standard POM fails when height maps are noisy. Micro-bumps on a brick face confuse the ray-marcher, causing visual artifacts. Our Smart Filter solves this.
- Adaptive Analysis: The shader analyzes the local contrast (Min/Max) of the height map.
- Selective Blur: It detects "Cliffs" (mortar lines) vs "Flats" (brick faces).
- The Result: It effectively ignores high-frequency noise on the flat surfaces (preventing artifacts) while keeping the deep structural edges perfectly sharp.
Cheat Sheet: Detail Suppression Modes
Choosing the right filter is key to balancing Detail vs. Stability.
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Basic / Fast
- NONE: Raw ray-marching. Sharpest, but prone to noise artifacts.
- FILTERED: Simple blur. Good for very noisy textures but loses detail.
- MINMAX: Clamps extreme peaks/valleys to stabilize the surface.
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Edge-Preserving
- BILATERAL: Blurs flat areas but preserves sharp structural edges (cliffs).
- BILATERAL_ADAPTIVE: Adjusts blur strength based on distance/angle.
- VARIANCE: Statistical filtering. Good for grainy surfaces like asphalt.
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Intelligent
- SMART: The recommended default. Combines structural analysis with adaptive filtering to perfectly separate "Brick" (flat) from "Mortar" (deep) without manual tuning.
The Native Advantage : True POM
Many node groups claim to do Parallax, but they often rely on simple "Iterative Offset" which creates banding artifacts. Rombo Image Parallax runs a compiled C++ ray-marcher directly in the kernel.
- Linear Only: Lacks Binary Search refinement, causing "stair-stepping" layers.
- No Self-Shadowing: Cannot calculate ambient occlusion because it's too expensive in nodes.
- Artifacts: Noise in the height map breaks the ray-marcher instantly.
- Binary Search: Refines the intersection point for perfect, smooth depth.
- Real Occlusion: Casts actual soft shadows from the height peaks onto the valleys.
- Smart Filter: Intelligently cleans the height map on the fly to prevent artifacts.
Parameters
Depth Controls
Shadowing
Smart Detail
SMART or BILATERAL_ADAPTIVE are recommended for textured surfaces to clean up noise.
Normals & Fade
Quick Recipes
Setup guides for common materials.
Paving Stones
- Depth 0.05
- Base Steps 32
- Occlusion 1.5
- Mode SMART
Sci-Fi Floor Grate
- Depth 0.2
- Base Steps 64
- Detail Suppr. 0.0
Noisy Concrete
- Depth 0.02
- Mode BILATERAL
- Suppression 0.5