Session Configuration

This guide covers all the configuration options available when setting up a photogrammetry session in Replica. Understanding these settings will help you balance quality, processing time, and output requirements for your specific needs.

Accessing Configuration Settings

When you're ready to start a reconstruction, click the Play button on your selected project. This opens the session configuration panel where you can adjust all settings before processing begins.

Configuration Presets (Pro Feature) 🌟

Before diving into individual settings, Pro users can take advantage of Configuration Presets to quickly apply commonly used settings.

Built-in Presets

Replica includes three default presets ready to use:

Preset	Best For	Settings
Quick Preview	Fast preview to verify capture quality	Preview detail with standard settings
Balanced	General-purpose reconstruction	Medium detail with standard settings
High Quality	Production-ready models	Full detail, sequential ordering, high sensitivity, quad primitives, object masking enabled

Managing Your Presets

To apply a preset:

• Select it from the "Configuration Presets" dropdown menu

To save a new preset:

1. Configure your desired settings
2. Click the + button next to the preset selector
3. Enter a name for your preset
4. Click Save

To delete a preset:

• Select the preset and click the trash icon

Tip: Create presets for different project types you work with regularly. For example, you might have one for "Product Photography" and another for "Architecture Models."

Model Detail

The Model Detail setting is the primary control for output quality and processing time. It determines the overall fidelity of your reconstructed 3D model.

Detail Level	Processing Speed	Quality	Best For
Preview	Fastest	Lowest	Quick verification of camera coverage and capture quality
Reduced	Fast	Low	Draft models, mobile app content, quick iterations
Medium	Moderate	Good	General-purpose models, web applications
Full	Slow	High	Production models, detailed visualization
Raw	Slowest	Highest	Maximum detail preservation, research projects
Custom	Varies	User-defined	Advanced users with specific technical requirements

When to Use Each Level

Preview & Reduced:

• Testing your photo set before committing to a long reconstruction
• Creating lightweight models for mobile devices or web viewers
• When time is more critical than quality

Medium:

• Most 3D models for general use
• When you need a balance between quality and processing time
• Models that will be viewed on desktop applications

Full & Raw:

• Final production assets
• Models requiring maximum detail capture
• When quality is the top priority and you have time to wait
• Creating models for close-up viewing or high-resolution rendering

Custom:

• When you have specific polygon count or texture requirements
• Advanced workflows with particular technical constraints
• Fine-tuning for optimal file size vs. quality trade-offs

Custom Detail Specification

When you select Custom as your Model Detail level, additional fine-grained controls appear that let you precisely define your output specifications.

Maximum Polygon Count

Define the upper limit for mesh complexity.

• Default: 250,000 polygons
• Type: Numeric value
• Impact: Higher values create more detailed geometry but increase file size and processing time

Consider this: A model with 100,000 polygons is suitable for most real-time applications, while 500,000+ polygons might be needed for high-detail visualization or animation projects.

Maximum Texture Dimension

Controls the resolution of texture maps applied to your model.

Resolution	Size	Recommended For
1K	1024 × 1024	Mobile devices, low-detail objects
2K	2048 × 2048	Web applications, standard quality
4K	4096 × 4096	Desktop applications, good detail
8K	8192 × 8192	High-quality production work (default)
16K	16384 × 16384	Ultra-high-resolution requirements, large objects

Tip: Texture resolution should match your intended viewing distance. Objects viewed from far away don't need 16K textures, while objects meant for close inspection benefit from higher resolutions.

Texture Format

Choose between lossless and compressed texture output.

PNG (Lossless)

• No compression artifacts
• Maximum quality
• Larger file sizes
• Best for: Production work, archival purposes, further processing

JPEG (Lossy)

• Adjustable compression quality (0.0 to 1.0)
• Smaller file sizes
• Quality vs. size trade-off
• Best for: Web delivery, when file size matters

JPEG Compression Quality Scale:

• 0.0 = Maximum compression (smallest files, lowest quality)
• 0.5 = Moderate compression (balanced)
• 0.8-0.9 = Light compression (great quality, reasonable size) (recommended)
• 1.0 = Minimum compression (highest quality, larger files)

Output Texture Maps

Select which texture map types to generate. Each map serves a specific purpose in rendering and visualization.

Texture Map	Purpose	When to Use
Ambient Occlusion	Simulates soft shadows in crevices and corners	Adds depth and realism to models
Diffuse Color	Base color information of the surface	Always needed for standard visualization
Displacement	Height map encoding fine surface detail	Creating geometric detail without extra polygons
Normal	Surface normal directions for lighting	Simulating detailed lighting on surfaces
Roughness	Surface roughness/glossiness properties	Controlling material reflectivity and appearance

Quick Selection Options:

• All: Generates all five texture map types (default for maximum flexibility)
• Custom: Toggle individual maps based on your specific needs

Save processing time: If you only need basic visualization, select just Diffuse Color and Normal maps. The other maps are primarily useful for advanced rendering in 3D applications.

Sample Ordering

This setting tells Replica how your input images are organized, which affects how the reconstruction algorithm processes them.

Option	How It Works	Best For
Unordered	Images processed without considering sequence	Photos taken from random positions around an object
Sequential	Images processed in the order they appear	Video frames, systematic photo sequences with planned camera paths

When to use Sequential:

• Your images come from a video file
• You captured photos in a systematic pattern (e.g., walking around an object)
• Images are named in chronological order

When to use Unordered:

• Photos were taken from various random angles
• You mixed different shooting sessions
• Image order doesn't reflect spatial relationships

Tip: If you're unsure, Unordered is the safer choice. It works well for most scenarios, while Sequential can provide slightly better results when your images truly follow a logical sequence.

Feature Sensitivity

Controls how aggressively the reconstruction algorithm detects and matches features between images.

Setting	Behavior	Processing Time	Best For
Normal	Standard feature detection	Faster	Most scenarios, objects with clear textures and features
High	Enhanced feature detection	Slower	Complex surfaces, fine details, subtle textures, challenging materials

Use High sensitivity for:

• Objects with low contrast or subtle textures
• Reflective or transparent surfaces
• Fine geometric details you want to capture
• When Normal sensitivity produces incomplete results

Use Normal sensitivity for:

• Objects with good texture and clear features
• When processing speed is important
• Most typical photogrammetry subjects

Mesh Primitive

Determines the type of polygons used to construct your 3D mesh. This choice affects compatibility and workflow integration.

Primitive	Description	Best For
Triangle	Standard 3-sided polygons	Game engines (Unity, Unreal), real-time rendering, maximum compatibility
Quad	4-sided polygons	CAD software, subdivision modeling, animation, further refinement in 3D apps

Choose Triangle if:

• Your model is destined for a game engine
• You need maximum compatibility across software
• The model will be used for real-time visualization
• You're exporting to web-based 3D viewers

Choose Quad if:

• You plan to edit or refine the mesh in Blender, Maya, or similar tools
• The model will be subdivided for higher detail
• You're creating assets for animation workflows
• The topology quality matters for further processing

Note: Most modern 3D software can handle both types, but triangles are more universally supported. When in doubt, choose Triangle.

Object Masking

Object Masking helps isolate your subject from the background during reconstruction, resulting in cleaner models with better-defined edges.

• Enabled: The reconstruction focuses on the primary subject, removing background elements
• Disabled: The entire scene is reconstructed, including background

Benefits of enabling Object Masking:

• Cleaner reconstruction with less background noise
• Better edge definition around your subject
• Reduced processing of irrelevant areas
• More accurate mesh boundaries

When to use Object Masking:

• Your subject is clearly distinct from the background
• You want to isolate a specific object
• Background contains distracting elements
• You're creating product models or isolated assets

When to disable Object Masking:

• You want to capture the entire environment
• The subject and background are equally important
• Creating architectural or landscape models

Important: Object Masking works best when there's good contrast between your subject and background. A clean, simple background (like a turntable) produces the best results.

Practical Configuration Examples

Here are some proven configurations for common scenarios:

Product Photography

Goal: Clean, high-quality model suitable for e-commerce or AR viewing

• Model Detail: Full
• Sample Ordering: Sequential (if shot on turntable)
• Feature Sensitivity: Normal
• Mesh Primitive: Triangle
• Object Masking: Enabled
• Texture: 4K JPEG (quality 0.9) or 8K PNG

Architectural Element

Goal: Detailed model for visualization in architectural software

• Model Detail: Full or Raw
• Sample Ordering: Unordered
• Feature Sensitivity: High
• Mesh Primitive: Quad
• Object Masking: Disabled
• Texture: 8K PNG with all texture maps

Web/Mobile 3D Viewer

Goal: Optimized model for web delivery with fast loading

• Model Detail: Custom
  • Polygon Count: 50,000 - 100,000
  • Texture Dimension: 2K or 4K
  • Format: JPEG (quality 0.8)
  • Maps: Diffuse Color + Normal only
• Sample Ordering: Unordered
• Feature Sensitivity: Normal
• Mesh Primitive: Triangle
• Object Masking: Enabled

Quick Preview Test

Goal: Fast verification of photo coverage before final reconstruction

• Model Detail: Preview or Reduced
• Sample Ordering: Unordered
• Feature Sensitivity: Normal
• Mesh Primitive: Triangle
• Object Masking: Disabled

Storage Requirements

Before starting a session, Replica automatically checks your available disk space. Higher quality settings require more storage during processing.

Approximate Storage Needs:

• Preview: < 1 GB
• Reduced: 1-3 GB
• Medium: 3-8 GB
• Full: 8-20 GB
• Raw: 20+ GB
• Custom: Varies based on polygon count and texture settings

The app will alert you if there isn't enough space available before processing begins.

Tip: Keep at least 20% of your disk free beyond the estimated requirement. Processing generates temporary files that need additional space.

Tips for Best Results

Start with a quick preview:

• Always run a Preview or Reduced quality reconstruction first
• Verify your photos have good coverage
• Check for any issues before committing to a long Full or Raw reconstruction

Match settings to your output:

• Don't use 16K textures if you're exporting for web viewing at 1080p
• Choose polygon counts appropriate for your target platform
• Consider your final delivery format when selecting texture formats

Experiment with presets:

• Pro users should create presets for their common workflows
• This saves time and ensures consistency across projects
• You can always fine-tune settings after applying a preset

Monitor processing time:

• Higher quality settings can take significantly longer
• Plan accordingly if you have deadlines
• Consider running overnight for Raw or high-polygon Custom reconstructions

Next Steps

Now that you understand all the configuration options:

• Getting Started - Learn the basics of creating your first photogrammetry project
• Workflows (Pro users only) - Discover how to automate post-processing operations

Need Help?

Visit the Replica community forums for support and tips from other users.

Happy reconstructing! 🎯