Unreal Engine Materials Guide: Setting Up Architectural Surfaces

What you’ll learn in this guide

This guide will help you think about surfaces used in Unreal Engine architectural visualization through the core material inputs. You’ll see how to handle the main color with Base Color, a surface’s metallic character with Metallic, reflection spread with Roughness, and transparency with Opacity. We’ll also look at some shading model options for distinctive material looks and why material inputs may be disabled.

An important note on scope: Epic’s “Material Inputs” document describes the general Unreal Engine material system. Not every input or shading model mentioned there should be treated as belonging to Substrate. Epic’s Substrate guide describes it as a separate material framework and carries a beta warning. The fundamentals below are based on the general material inputs guide.

Requirements and scope

• Software: The sources cover the Unreal Engine 5 material system and Substrate. No specific 5.x minor version is given.

• Account and license: The source documents do not provide information about account requirements, license fees, or subscriptions.

• Prior knowledge: It’s useful to understand what the terms Material Domain, Blend Mode, and Shading Model affect. They can determine which material inputs are available.

• Substrate warning: Epic labels Substrate as a beta feature and recommends caution when using it in shipped projects.

According to Epic, Substrate replaces a structure tied to predefined shading models with a more flexible, component-based material approach. However, it would be incorrect to automatically treat the settings in the general “Material Inputs” document as part of the Substrate workflow. Keeping the scope of the two documents separate helps avoid false expectations, especially before project delivery.

Step by step: setting up basic surface properties

1. Determine the material’s purpose and properties

If an input is missing or unavailable, first check the material’s Blend Mode, Shading Model, and Material Domain settings. According to Epic’s documentation, these three properties control which inputs are enabled. For example, a Translucent Blend Mode can be used when a glass-like surface needs the Opacity input.

When setting up a material, first decide whether it’s an ordinary or transparent surface. If a required input is disabled, check the relevant material properties rather than changing the texture straight away. This lets you look for the issue in the setting that controls it.

2. Use Base Color for the surface’s base color

Base Color sets the material’s overall color. Epic explains that this input should represent the diffuse light reflected from the surface; specular reflections are not included in that definition. So for an architectural scene, think of this as the main color information for paint, stone, or wood. Don’t try to control glossiness and reflection character with the same setting.

If you’re using base color textures sourced from the real world, the documentation notes that taking photos with a polarizing filter can reduce specular reflections on non-metal surfaces. If you don’t know whether this was done for the textures you have, don’t treat the color information alone as a definitive physical measurement.

3. Choose the Metallic value based on the material type

Metallic is an input that determines how metallic a surface behaves, and it takes values between 0 and 1. Epic’s general material guide recommends 1 for pure metal surfaces and 0 for pure non-metal surfaces. So don’t make surfaces such as stone, plastic, or wood metallic just to make them look shinier.

Mixed surfaces, such as rusty, dusty, or corroded metal, may require intermediate values. When creating a Metallic mask, use black and white values unless you specifically want a transition between metal and non-metal areas. Gray values can indicate a blend between the two characteristics.

4. Control reflection sharpness with Roughness

Roughness controls whether reflections appear sharp or diffuse. Epic’s explanation associates a value of 0 with a mirror-like response and 1 with a matte, more diffuse surface response. In architectural scenes, this setting helps establish the visual difference between a polished surface and one that’s worn or matte.

Most surfaces aren’t equally rough at every point. A Roughness map can be used for scratches on metal, wear on a wood floor, or fingerprints on plastic. First establish the overall surface character, then add localized variation with a map if it’s genuinely needed. This helps keep minor surface marks from overwhelming the material’s overall appearance.

5. Use different methods for transparency and cutout surfaces

The Opacity input can be used with blend modes such as Translucent, Additive, and Modulated. An Opacity value of 0 makes the material fully transparent; 1 makes it fully opaque; and values in between produce partial transparency. If the Opacity input needs to be available for a glass-like surface, Epic’s example recommends changing the Blend Mode to Translucent.

Opacity Mask serves a different purpose. Instead of producing partial transparency, it makes surface areas fully visible or fully invisible. This can be useful for a perforated surface such as a wire mesh. In Epic’s example, with a threshold of 0.5, pixels above that value become opaque and those below it become transparent. So don’t use the same method for glass and perforated surfaces.

6. Consider specialized surface options with their scope in mind

In the general material inputs document, Clear Coat is described as a shading model for simulating a thin coating layer. Furniture varnish and metal covered with a colored film are among the examples given in the general explanation. The Clear Coat input controls the amount of the layer, while Clear Coat Roughness controls its roughness. Epic notes that very rough coating values are supported, but may not represent their real-world counterparts with the same accuracy.

This explanation doesn’t mean Clear Coat can be used the same way in Substrate. The Substrate guide describes a separate framework that replaces the fixed shading model approach. So don’t present general material knowledge about Clear Coat as a Substrate-specific feature; verify your project settings and the material approach you’re using separately.

For anisotropic surfaces, the general material document describes the Anisotropy and Tangent inputs. Brushed metal is one of its examples of directional reflection. The document states that Anisotropy ranges from -1 to 1, and that a value of 0 produces no anisotropic effect. The feature’s operation depends on supported Gen5 platforms and High, Epic, or Cinematic scalability settings. These requirements make it important to test the result on the intended target.

Common mistakes

• Using the same Metallic value for every material: Distinguish pure metals from non-metal surfaces; reserve intermediate values for mixed surfaces.

• Confusing Base Color with reflection: Treat overall color and specular reflection as separate material properties.

• Expecting partial transparency from Opacity Mask: The mask makes areas visible or invisible; partial transparency for glass-like surfaces is handled with Opacity.

• Ignoring why an input is disabled: Check the Blend Mode, Shading Model, and Material Domain settings.

• Attributing general material properties to Substrate: The sources treat the scope of these two documents separately; don’t transfer every option from one to the other.

Architectural visualization workflow and next steps

These distinctions help you prepare surfaces such as stone, metal, glass, and wood not just by their color, but also by how they reflect light and handle transparency. For architecture and interior design teams, the most practical starting point is to identify the surface type and make separate decisions for Base Color, Metallic, and Roughness. For transparent or perforated surfaces, keep in mind the different roles of Opacity and Opacity Mask.

Teams evaluating Substrate should pay attention to two points: Epic’s beta warning and the fact that the options in the general material inputs document don’t automatically belong to Substrate. Validate materials under the project conditions in which the scenes will be delivered. If you need anisotropy, review the platform and scalability requirements stated in the documentation. In the next stage, change one surface property and observe the result; this helps you distinguish the visual impact of different settings.

Sources and license

This tutorial was adapted into Turkish using Epic Games’ “Substrate Materials” and “Material Inputs” documentation. Both sources are provided as license=free. Material inputs are covered as part of the general Unreal Engine material system and are not claimed to be specific to Substrate.