HARD SURFACE | MECHANICAL DESIGN
Technical details
| Technical Field | Information |
| Project | Hard Surface |
| Production | Personal proyect |
| Category | Hero Prop |
| Type | Mid Poly Asset · Hard Surface |
| Software | ZBrush · 3ds Max · Marmoset· Adobe Substance 3D Painter · V-Ray · Unreal Engine 5 |
| Deliverables | Hero Prop |
| Texture Resolution | 9 Texture Sets · 4K |
| Rendering | Real Time · Offline |
| Lighting | Lumen |
| Geometry | Nanite |
| Duration | ≈ 2 weeks |
Project Goal
Hard Surface is a personal project developed with the goal of deepening advanced mechanical modeling techniques and completing a production pipeline focused on the development of a highly complex Hard Surface asset.
Unlike an asset optimized exclusively for video games, this project was conceived as a Mid Poly Asset, seeking a balance between geometric quality, structural efficiency, and versatility that would allow the model to be reused in different production contexts.
The project was designed with a clear production-oriented approach, prioritizing the construction of clean geometry, a coherent hierarchical organization of the mechanical assemblies, and a workflow methodology that allowed the asset to remain easily editable throughout all phases of development.
The purpose was not only to achieve a good visual result, but to develop a technically solid asset whose structure could easily adapt to different production needs, maintaining geometry quality, topology stability, and model reuse throughout the entire pipeline.
Responsibilities
Production pipeline
High Poly → Middle Poly → UV Layout → Texel Density → Bake → Texturing → Render Validation → Final Presentation
Workflow
High Poly
Production began directly from a collection of technical blueprints with real dimensions that accurately defined the structure, proportions, and relationship between all the asset's mechanical subassemblies. By having completely defined documentation, a prior Blocking phase was not necessary, allowing the construction of the final model to start directly.
The High Poly was developed entirely in ZBrush, leveraging the Dynamic Booleans system to build the model's complex mechanical structure and efficiently resolve intersections between the different components throughout the production process.
From the early phases, work was carried out with a properly organized topology using ZModeler, establishing a clean Edge Flow and an adequate distribution of the Support Loops required to precisely control surface radii, maintain continuity between parts, and guarantee a clear reading of each mechanical assembly.
This approach allowed for continuous iteration on the design without reconstructing geometry, maintaining high control over surface continuity and establishing a solid foundation to handle the subsequent retopology process.
Middle Poly
Once the High Poly was finalized, a Middle Poly version was developed through a specific retopology process aimed at completely reorganizing the asset's geometry without compromising its visual fidelity.
The first topological redistribution was performed in ZBrush, using Polygroups to define the model's different functional regions and generate a new base via ZRemesher.
Subsequently, the retopology was manually refined by combining ZModeler and 3ds Max, reorganizing the Edge Flow, optimizing the distribution of structural loops, and simplifying areas where polygon density could be reduced without affecting the mechanical reading of the assembly.
During this phase, all non-visible faces were also removed and welds were performed on strategic vertices to reduce the geometric load, improve mesh continuity, and obtain a clean structure prepared for the next phases of the pipeline.
The result was a Mid Poly Asset capable of retaining the formal fidelity of the High Poly while offering an optimized, stable geometry easily reusable in different production environments.
UV Layout · Texel Density · Bake
After completing the Middle Poly version, the UV Layout was developed, organizing each mechanical subassembly independently to maintain a logical distribution of the UV islands and maximize the use of the available space.
Due to the structural complexity of the assembly and the project's purpose as a reusable asset for different production pipelines—including real-time rendering using Unreal Engine 5 and offline rendering with V-Ray—the model's organization was resolved using 9 4K Texture Sets. This division does not only respond to resolution criteria, but also to the functional organization of the asset, grouping related mechanical components to facilitate iteration during texturing, project maintenance, and a possible subsequent reorganization according to production needs.
The combination of this structure with a high-density Mid Poly geometry allows that, during its integration into Unreal Engine 5 using Nanite, the fidelity of the volume and silhouette depends mainly on the geometry itself, relegating the PBR maps to surface detail (Base Color, Normal, Roughness, and micro-detail) and reducing the need to rely on high-resolution displacement maps.
The UV Layout was optimized maintaining a high occupation in each Texture Set (≈70–90%) and a uniform Texel Density of 18.35 px/cm (1835 px/m Target Resolution). This strategy guarantees a homogeneous resolution across all mechanical subassemblies, avoiding noticeable variations in the level of detail between parts regardless of the Texture Set they belong to and establishing a consistent foundation for the Bake process.
To ensure an artifact-free Bake (free of skewing and sub-pixel aliasing), a workflow based on Bake Groups using a strict naming convention (_high / _low) was implemented in Marmoset Toolbag. The segmentation of the UV islands strictly coincides with the Smoothing Groups (Hard Edges), additionally applying a 16-pixel padding to prevent texture bleeding during 4K texture mipmapping.
Each of these decisions responds to standard production criteria aimed at obtaining a clean, consistent, and easily maintainable Bake during future iterations of the asset.
Texturing
The texturing process was developed entirely in Adobe Substance 3D Painter, following a non-destructive layer-based PBR workflow.
The material strategy focused on reinforcing the functional credibility of the asset through the combination of roughness variations, surface micro-detail, and controlled differences between materials that break surface uniformity without introducing unnecessary visual noise.
Instead of applying wear arbitrarily, each texturing decision responds to the model's own mechanical construction, distributing material use, finish changes, and surface variations where they have a functional justification. This approach improves the asset's structural reading, clearly differentiates the various components, and maintains the visual coherence of the entire assembly.
The goal was not to hide the geometry through texturing, but to complement it, reinforcing the sense of scale, the physical behavior of the materials, and the overall credibility of the model within a production pipeline.
DIFUSSE/ROUGHNESS/METALLIC/NORMAL
Render Validation
As the final phase of the pipeline, the asset was validated in two different rendering environments with the goal of testing its behavior under different production contexts.
In Unreal Engine 5, the integration allowed verifying the asset's real-time performance using Nanite and Lumen, evaluating the PBR material reading, lighting response, and the model's overall behavior within a video game engine.
In parallel, the model was rendered using V-Ray, allowing for the validation of geometry quality, surface continuity, and material response within an offline rendering pipeline.
This dual validation made it possible to verify that the asset maintains the same technical and visual coherence regardless of the rendering environment used, reinforcing its versatility for different types of production and verifying that all decisions made during development respond correctly in both real-time and offline rendering.
