Lumion's AI PBR Material Generator includes concrete as one of its five preset material categories. For architects inside the Lumion ecosystem building client presentations with site-specific concrete finishes, this is a useful feature. For anyone working in Blender, Unreal Engine 5, Unity, Godot, or any renderer other than Lumion — or for anyone not paying $60-75+/month for a Lumion subscription — the concrete material workflow requires a standalone tool.

This guide covers text-to-PBR concrete generation for cross-platform workflows, including prompt techniques for board-formed, polished, and aged concrete, plus engine-specific import notes for Blender and Unreal Engine 5.

What Lumion's Concrete Preset Does (and Doesn't Do)

Lumion's concrete preset is photo-to-PBR: supply a reference image of the concrete surface you want to reproduce and the tool extracts PBR maps calibrated for Lumion's rendering engine. For matching a specific real-world concrete finish — an on-site poured wall, a precast panel from a manufacturer's sample — this is a practical workflow if the surface is photographable and you're rendering in Lumion.

The constraints are consistent with Lumion's other AI material presets. Photo dependency limits generation to surfaces that can be photographed — stylized or imagined concrete finishes aren't accessible. Renderer lock-in means the output doesn't export as portable PNG maps for use outside Lumion. And the subscription cost ($60-75+/month) is a high baseline for teams whose primary need is PBR texture generation rather than full architectural rendering.

Text-to-PBR Concrete Generation

Grix generates concrete PBR textures from text descriptions with no photo input requirement and no renderer lock-in. Describe the concrete type, finish, and any damage or weathering at grixai.com/try — free trial, no login — and receive a ZIP of five PBR maps: basecolor, normal, roughness, metalness, and height. Maps tile seamlessly and import into any renderer accepting standard PBR inputs.

Pricing starts at $8/month for the Light plan, compared to $60+/month for a Lumion subscription. The free trial produces full-resolution output with no account required.

Concrete Prompt Techniques for PBR Quality

Concrete is one of the richest categories for prompt-driven PBR generation because concrete finish quality varies so dramatically with formwork, mix, age, and treatment. These elements drive the most visible differences in output:

Formwork type. "Board-formed concrete" produces horizontal wood grain impressions in the normal map — the texture left by the boards used to form the pour. "Smooth formwork concrete" produces a near-flat surface with fine pore detail. "Rough aggregate concrete" produces a heavily textured normal map where aggregate stones break the surface. "Fair-faced concrete" (Sichtbeton) produces a clean, lightly pored surface associated with contemporary architecture — minimal imperfection, precise joint lines where formwork panels meet.

Age and exposure. "Fresh poured concrete" gives a uniform pale grey basecolor with minimal variation. "Aged exposed concrete" introduces carbonation staining — darker at the base, lighter at protected areas. "Weathered outdoor concrete" adds moss patches, surface scaling, and water-stain discoloration in the basecolor with corresponding normal map surface roughening. "Historic concrete, decades-old" introduces spalling and aggregate exposure visible in both basecolor and the normal map as surface pitting.

Surface treatment. "Polished concrete, mirror finish" drops roughness to 0.15-0.25 with high specular response — appropriate for contemporary commercial interiors. "Honed concrete" sits at 0.35-0.45 roughness. "Sandblasted concrete" increases roughness to 0.75-0.85 and removes the surface paste to reveal aggregate. "Acid-etched concrete" produces a lightly textured surface at 0.65-0.7 roughness with subtle aggregate visibility.

Color and staining. "White cement concrete" shifts the basecolor toward cool white-grey. "Pigmented concrete, warm earth tone" introduces iron oxide coloration. "Carbon-stained industrial floor" adds dark patches in high-traffic areas. "Efflorescence on concrete wall" produces white salt deposits at joints and surface cracks — a common aging pattern in exterior architectural concrete.

Concrete Prompt Examples

Contemporary architectural concrete: "Fair-faced concrete, smooth formwork, pale warm grey, fine surface pores, subtle horizontal joint lines, 0.7 roughness" — the canonical Tadao Ando-influenced contemporary concrete surface.

Board-formed feature wall: "Board-formed concrete, horizontal pine board impressions, dark grey, pour lines visible, occasional tie-hole recesses, 0.8 roughness" — character-appropriate for hospitality, residential, or museum interior visualization.

Polished commercial floor: "Polished concrete floor, aggregate exposure, mid-grey with brown gravel aggregate visible, 0.25 roughness, mirror-like sheen at low angles" — contemporary commercial or residential floor material.

Aged exterior wall: "Aged outdoor concrete retaining wall, 30 years old, carbonation staining, moss at base, hairline cracks, heavy weathering, 0.85 roughness" — appropriate for landscape architecture or game environments needing historical context.

Industrial floor: "Industrial concrete floor, sealed, oil staining in forklift paths, scuff marks, worn surface at edges, 0.6 roughness" — warehouse, factory, or urban game environment material.

Precast panel: "Precast concrete panel, exposed aggregate finish, small smooth pebbles at surface, light grey cement paste background, uniform pattern, 0.8 roughness" — contemporary facade material for architectural visualization.

Blender Import Workflow for Concrete

In Blender, concrete benefits significantly from displacement. Board-formed and aggregate concrete surfaces have physical depth that normal maps approximate but height map displacement reads more convincingly — especially in Cycles with adaptive subdivision active.

Enable Adaptive Subdivision on the mesh. Set displacement to "Displacement and Bump" in Material Properties. Connect the height map to the Displacement input of Material Output through a Displacement node. Displacement scale: 0.005-0.015m for smooth architectural concrete; 0.015-0.04m for rough aggregate or heavily weathered surfaces.

Set Image Texture color space to "Non-Color" for all maps except Basecolor (which should stay at sRGB). Grix outputs OpenGL-convention normal maps — no channel flip needed in Blender. Connect Normal to Normal using a Normal Map node (tangent space).

For large architectural surfaces like walls and floors: a Mapping node controlling UV scale lets you set tile frequency. At 1.0 UV scale, most concrete textures represent approximately 0.5-1.5m of physical surface. A 4m wall height at a scale representing 1.0m per tile needs 4 UV repeats vertically. Use a Texture Coordinate node feeding into the Mapping node for UV-based tiling.

Unreal Engine 5 Import Workflow

UE5 expects DirectX normal convention. Flip the green channel on import for the normal map — enable "Flip Green Channel" in the texture import dialog or in the Texture Editor after import. All other maps import without modification.

For polished concrete floors with high specular response: set roughness values will be low (0.15-0.3 depending on polish level). In a BRDF-based UE5 material, low roughness produces correct mirror-like reflection at grazing angles without additional configuration.

For Nanite displacement on large concrete structures: connect Height to World Displacement with a multiply scale of 0.5-2.0cm depending on surface type. Enable Nanite Displacement in the mesh's Nanite settings. Virtual Textures are recommended for large concrete facades and floors where the texture tiles across hundreds of square meters.

See grixai.com/pricing for the free trial and paid plan details.

Frequently Asked Questions

Can Grix generate board-formed concrete texture from a description?

Yes. Specify "board-formed concrete" with board width, direction, and any visual details like tie holes or pour lines. The normal map will reflect the formwork impression geometry and the basecolor will show the characteristic dark horizontal shadow pattern between boards.

How does Grix concrete compare to Lumion's concrete preset?

Lumion's preset requires a reference photo and outputs materials optimized for Lumion's renderer. Grix generates from text description alone and outputs portable PNG map sets that import into any renderer: Blender, Unreal Engine, Unity, Godot, and others. Grix starts at $8/month; Lumion starts at approximately $60-75/month.

Can I generate aged or damaged concrete from text alone?

Yes. Weathering, carbonation staining, moss, spalling, and crack patterns can all be described in the prompt. "Aged outdoor concrete, 40 years old, carbonation staining, hairline cracks, surface scaling" produces a convincingly weathered material without requiring a physical sample to photograph.

What roughness values should I expect for different concrete types?

Polished concrete: 0.15-0.35. Smooth architectural concrete (fair-faced): 0.55-0.7. Standard formed concrete: 0.7-0.8. Sandblasted or rough aggregate concrete: 0.8-0.9. Heavily weathered outdoor concrete: 0.85-0.95. Specifying the finish type and roughness target in the prompt produces maps calibrated to those values.

Does the free trial produce full-quality output?

Yes. The grixai.com/try free trial produces the same full-resolution five-map PBR output as paid plans, with no account required.