Have you ever tried to build a complex 3D geotechnical model? We feel your pain. Hours spent fixing geometry defects, objects that do not perfectly match up, and the constant battle to simplify excessive triangle densities. You're not alone, and the solution might finally be within reach.

The Universal Struggle: It's Not Just Geotechnical

Before diving into our specific challenges, it is worth noting that 3D geometry problems plague virtually every engineering discipline. Medical device manufacturers struggle with CT scan artifacts when developing patient-specific implants. Aerospace engineers must identify and resolve surface irregularities when they scan flight-critical components for maintenance and repair purposes. Manufacturing teams experience casting simulation failures due to non-watertight computational mold geometries. Marine shipbuilders wrestle with intricate networks of structural elements that create countless geometric intersections and penetrations.

The oil and gas industry encounters identical issues when creating 3D pipeline network models with corrosion defects and multiple interacting components. Architecture and construction battle geometry repair challenges when integrating BIM models from multiple disciplines.

The pattern is clear: robust 3D geometry handling is a critical foundation. Without it, advanced computational workflows cannot reach their full potential across all engineering domains.

The Geotechnical Pain Points: A Catalog of Frustration

In 3D geotechnical modelling, these recurring geometry challenges (read nightmares) manifest in the following forms:

• Near-Degenerate Triangles: Those impossibly thin triangles with near-zero areas that affect geometry operations and create computational instabilities during numerical analysis.
  
  
• Holes and Open Boundaries: Missing faces that make your volumes "leaky", prevent proper material assignment and can cause geometry Boolean operations to fail.
  
  
• Non-Manifold Geometry: The dreaded shared edges between multiple volumes that create topologically invalid models and are a guaranteed showstopper for many 3D geometry operations.
  
  
• Inconsistent Triangle Normals: When surface orientations point randomly inward and outward, they lead to incorrect volume calculations and bizarre material property assignments.
  
  
• Tiny Gaps and Overlaps: Those tiny separations between geological layers or excavation objects that seem insignificant but create massive computational meshes or cause simulation instability.
  
  
• Self-Intersecting Surfaces: Folded or twisted geometry that violates basic mathematical principles and breaks processes that depend on clean, accurate 3D geometric models as input.
  
  
• Interface Mismatch in Shared Boundaries: Perhaps, one of the most insidious problems: when you simplify densely triangulated geological volumes separately, their previously perfect interfaces no longer align, creating gaps or overlaps that compromise the entire model.

Why This Keeps 3D Modelling from Going Mainstream

The challenges we have described are not just annoying—they are adoption barriers that prevent 3D geotechnical modelling from becoming as routine as 2D analysis. Every practitioner has experienced the following frustrations:

• Time Drain: Geometry cleanup can consume 60-90% of modelling time, turning what should be routine analysis into pitched battles.

• Expertise Barrier: Success requires a deep understanding of computational geometry—knowledge that most geotechnical engineers should not need.

• Workflow Interruption: The constant stop-and-fix cycles break modelling momentum and discourage adoption.

The harsh reality: Until we solve these geometry challenges, 3D geotechnical modelling will remain a specialist tool rather than mainstream practice.

The Current Workaround: Combinations of Geometry Cleanup Tools

While we work toward ultimate solutions, Rocscience's 3D software suite provides a comprehensive toolkit that, when creatively combined, can address most geometry challenges:

Core Repair Tools:

• Retriangulate: Rebuilds surface meshes with improved triangle quality.

• Simplify Triangulation: Reduces mesh density while preserving essential features.

• Form Closed Triangulation: Creates watertight volumes from open surfaces.

• Merge: Consolidates nearby vertices within tolerance.

• Ungroup Non-Manifold: Isolates and splits problematic shared geometry.

• Ungroup Disjoint: Splits triangulated objects into multiple disconnected parts when imported geometries contain multiple separate objects incorrectly grouped together.

• Repair: Designed to detect and fix five major categories of geometry defects - near-degenerate features, holes, near-folding, self-intersections, and non-manifold geometry - automatically.

• Divide All: The heavy-duty intersection resolver that can also handle tiny gaps, overlaps, and complex multi-object intersections.

• (New) Shrink Wrap: Generates clean enveloping surfaces around geometry objects.

Strategic Workflow:

The key is understanding when and how to combine these tools. For example, for densely triangulated, perfectly abutting geological volumes, you can do the following:

• Separately simplify the triangulations of the volumes, which creates the interface mismatch problem—where simplified geological volumes no longer align at boundaries.
  
• Use Divide All with appropriate tolerance to perform 3D Boolean operations and resolve mismatches.
  
• Fine-tune outcomes with targeted repair tools (such as Collapse Small Volumes or Collapse Material Boundaries) for remaining issues.

As you can see, the challenge is not the lack of capabilities—it is knowing which combination of tools to use for each specific scenario and optimizing the parameter settings for a particular geometry process.

The Ultimate Solution: AI-Powered Geometry Intelligence

3D geometry challenges are an area where artificial intelligence can revolutionize our workflow. The emergence of sophisticated AI agents like ChatGPT Agent and Perplexity's Comet demonstrates the potential for AI to understand complex, multi-step processes and execute them intelligently.

While current AI agents primarily work with web-based interfaces, the transition to desktop applications is inevitable. The underlying technology—natural language processing, computer vision, and workflow automation—translates directly to desktop environments. We are likely months, not years, away from AI agents that can:

• Analyze 3D geometry directly within CAD applications for patterns in geometry defects.

• Recommend optimal repair sequences based on defect types and severity.

• Execute complex repair sequences automatically.

• Learn from successful repair workflows to improve future recommendations.

• Automate parameter selection based on model characteristics, and

• Provide real-time guidance during model construction.

Shrink Wrap Tool: Automated Geometry Envelope Creation

Rocscience has implemented a powerful new Shrink-Wrap tool that will revolutionize how users handle problematic 3D geometries in their modelling workflows. This innovative feature creates a watertight, simplified mesh "envelope" that tightly wraps around one or more selected geometry volumes, effectively generating clean, well-behaved geometry from complex or defective input models. You can think of it as digitally wrapping your geometries in shrink-wrap plastic – the tool analyzes the overall shape and creates a new, simplified outer surface that follows the contours of your original geometry while eliminating internal defects, holes, overlaps, and non-manifold issues.

What makes this new tool particularly valuable for geotechnical modelling is its batch processing capability, which allows users to wrap multiple geometry objects simultaneously rather than processing each one individually. This batch functionality dramatically improves efficiency when dealing with complex multi-volume assemblies, such as various geological units or excavations. It ensures that all processed volumes maintain consistent quality and are immediately ready for mesh generation and numerical analysis. The shrink wrap tool essentially transforms fragmented, defective, or overly complex geometry into robust, analysis-ready, watertight volumes.

Performance Optimization: Sequential Divide All

Another immediate improvement we are implementing addresses a key bottleneck in current workflows. Divide All, while powerful, faces performance challenges with complex, heavily triangulated geometries because it does not perform intersections in parallel.

Our sequential Divide All implementation automatically optimizes processing by:

• Breaking large intersection problems into manageable batches

• Processing geometries incrementally rather than simultaneously

• Maintaining topological consistency across sequential operations

• Dramatically reducing computation time for complex multi-object scenarios

This approach transforms an O(n²) problem into multiple O(b²) problems where b << n, providing exponential performance improvements for large models.

The Path Forward

3D geotechnical modelling is at a tipping point. We have the computational power, the geometric algorithms, and increasingly sophisticated repair tools. What we need now is the intelligence layer that makes these capabilities accessible to practitioners focused on engineering rather than geometry debugging.

The combination of immediate workflow improvements (better geometry repair tools and sequential processing) with emerging AI capabilities (intelligent defect recognition and automated repair workflows) promises to finally eliminate the geometry barriers that have kept 3D modelling from mainstream adoption.

The geometry nightmare that has plagued 3D modelling for decades is not going to last forever—it is a solvable problem that we are actively working on.

The future of 3D geotechnical modelling is not just about better algorithms—it is also about intelligent systems that handle geometry complexity, letting engineers focus on what matters: understanding ground behaviour and designing safe, efficient solutions.

Want to take a deeper dive? Keep an eye out for Rocscience’s upcoming webinars on 3D geometry workflows in RS3 and Slide3, along with our new training course designed to help you sharpen your modelling skills.

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