Process Study

Photogrammetry Pipeline

An exploration of photogrammetry workflows, from image capture to game-ready assets.

MeshroomBlenderInstant MeshUnity

Meshroom Workflow

I started by processing 120 images of a tree trunk through Meshroom's photogrammetry pipeline, learning the core steps of the process.

Pipeline Steps

01
CameraInit: Load images and detect camera properties automatically
02
FeatureExtraction: Extract image features for later matching
03
ImageMatching: Compare features across multiple images
04
FeatureMatching: Check correspondences and align images
05
StructureFromMotion: Build 3D structure using matched features
06
DepthMap & Filter: Create and filter depth maps for accuracy
07
Meshing: Generate 3D model from depth data
08
Texturing: Apply image textures to the mesh
Computation Time

1-2 hours total. DepthMap and Meshing were the most time-consuming steps, each taking about 30 minutes.

Challenge

DepthMap computation seemed stuck. Fixed by adjusting parameters to lower values based on online research.

Image Capture Process

This is where I learned the most, honestly through messing up. I tried to capture a scooter, car, top hat, and a smurf figure. Most of them didn't work out.

What Went Wrong

  • -Wrong format: iPhone saved as HEIC instead of JPG, requiring time-consuming conversion
  • -Single position capture: Rotating the object from one spot produced nearly identical images with no angle variation
  • -Insufficient feature points: Meshroom rejected images due to lack of variation for matching

Lessons Learned

  • - Ensure correct image format before capturing
  • - Pick static objects with clear, distinct features
  • - Move around the object, don't just rotate it from one spot
  • - Take varied angles, photogrammetry needs diversity

Mesh Cleaning & Retopology

Revisiting the tree trunk model, I focused on making it game-ready through cleanup in Blender and retopology in Instant Mesh.

Blender Cleanup

  • - Used Lasso tool + X-ray view to isolate unwanted elements
  • - Removed noise from pebbles and ground around base
  • - Filled holes at the top using Fill tool

Instant Mesh Retopo

  • - Set target vertex count to 3,000
  • - Used Solve Orientation for cleaner edge flow
  • - Ran Solve Position for accurate shape fitting

Poly Count Comparison

33M+

High-poly from Meshroom

Too heavy for real-time use

~3,000

After retopology

Game-ready with preserved shape

The Alchemy Lab Scene

I designed an atmospheric "Alchemy Lab" scene combining photogrammetry with shader-based visual effects.

Concept

A small exploration space where everyday scanned objects become mystical artifacts. Players can interact with objects to trigger shader effects, like clicking a flask to see liquid bubble, hovering over a potion to reveal a glow or particle effect.

Technical Focus

  • - Shader effects for glowing liquids
  • - Reflective glass materials
  • - Particle effects for dust and magical sparks
  • - Optimized for real-time performance

Goals

  • - Portfolio piece for shader development
  • - Immersive visuals with simple interaction
  • - Demonstrate VFX in photogrammetry context

Key Takeaways

Preparation Matters

Camera settings, image format, and capture strategy should be planned before shooting.

Fail Fast, Learn Faster

The failed image captures taught more than the successful ones.

Pipeline Thinking

Understanding the full workflow from capture to game-ready asset is essential.