James MarlandTechnical Artist - Tools, Pipelines & Shaders

Breakdown 2 of 5

Master materials

I made every master material in the game, including neon holo signs and vertex paint blends broken up with world space noise.

Overview

I made every master material in the project. The artists used 4 of them most: Opaque, Sign (a hologram-style master), Blend and Decal.

The Masters folder in the Unreal content browser, fifteen material spheres: M_MasterBlend, Character, Decal, FlipbookPanner, Fog, Hologram, Landscape, Masked, Opaque, Sign, SimpleEmissive, Skyscraper, Transparent, Water and M_SimpleFoliage
All 15 masters.

I repeatedly added features as the artists asked for them, sorted the parameters into artist-friendly groups so each material was easy to customise, and weighed each request against its rendering cost.

Vertex painting, the Opaque master and the Sign master in the editor.

Opaque

This is the general-purpose material, used on most props and architecture. Most of it is the usual tint, emissive and overlay controls, plus a setting for the ink lines.

Borderlands paints black ink lines straight into the diffuse texture. On a metallic or glossy surface those lines would catch reflections and stop looking like ink, so the Opaque master thresholds the diffuse into a mask of the lines, removes them from the metallic channel and pushes them to full roughness.

The M_MasterOpaque material graph in Unreal, split into coloured comment boxes: Base - Import Textures in red, Emissive in orange, Overlay in green, a teal Outline box labelled Omit from metallic and roughness channel (Helps makes it pop), and the Material Attributes output
The Opaque master. The teal box handles the ink lines.
Opaque master’s parameters

Base

Textures
Strengths
Tint
Override roughness

Emissive

Overlay

Outline

  • float
  • bool
  • vector
  • texture
The Opaque master's defaults.

Sign

Lectra City is covered in neon and holographic signs, and these are replicated with the Sign master. Each effect, like the distortion, scanlines and faults, is its own parameter group with an on switch, and they’re all multiplied together at the end into the emissive colour and opacity. It was intended to be highly customisable so it could be used anywhere. Two examples are shown below.

Flag hologram.
BANG billboard.

Here’s a comparison of my sign implementation and one from Borderlands 3, with the 2D graphic by Milly.

Two holographic signs side by side. On the left, mine in Borderline Racing: a yellow outlined figure above a column of outlined letters, glowing up a sandstone wall from a lit base. On the right, a holo sign in Borderlands 3: a zigzag of pink and yellow shapes rising from a metal projector on the side of a building.
Ours - left, Borderlands 3's - right.

This is the sign master graph. The coloured comment boxes are for the scanlines, noise, pulse and faulty effects, and the Material Attributes box clamps them into emissive colour and opacity.

Part of the M_MasterSign material graph in Unreal: coloured comment boxes for the scanlines, noise, pulse and faulty effects on the left, feeding a Material Attributes box on the right where the effects are multiplied together and clamped into emissive colour and opacity
The Sign master.
Sign master’s parameters

Screen

Screen size
Icon size

Distortion

Jitter

Texture

Scanlines

Switch
Scanline 1
Scanline 2
Scanline 3

Noise

Pulse

Faulty

Hex

Final effects

  • float
  • bool
  • texture
The Sign master's defaults.

Blend

A big artist request was the vertex painting system. They liked the ground but wanted to be able to break it up and have complete control of where. To accommodate this, I set up the system, wrote documentation and taught the artists how to use it. An artist can paint up to four layers over a base material, one vertex colour channel per layer, and the textures are world aligned so they line up across meshes.

A paved square from above with patches of grass, dry dirt and pebbles painted over the paving stones, the edges of each patch broken up irregularly, beside a building's front steps and two rusty barrels
Grass, dirt and pebbles painted over the paving.

It’s built on Unreal’s material layers. Each surface, like dirt or grass, is an instance of the same layer material, with the Opaque master’s controls plus a world aligned switch, and each layer sits on the one below it through a blend.

The Blend folder in the Unreal content browser: ML_Ground Layer, MLB_Ground Blend and layer instances including MLI_Dirt, MLI_Grass, MLI_Gravel and MLI_Mud, shown as material spheres
One layer material, many instances.

Painted vertex colour on its own gives a soft, smeared gradient, and on a low-poly mesh it shows exactly where each vertex sits. To break that up, the blend mixes the painted value with a noise texture sampled in world space before it drives the alpha. The texture packs a different noise into each channel, so each material instance picks the kind of edge it wants by choosing a channel:

v     = one vertex colour channel, inverted by default
n     = chosen channel of the packed noise texture, sampled at world XY / 1000 * Noise Scale (0.8)
alpha = CheapContrast( saturate(2v + n - 1), Noise Contrast (2.0) )

Around the middle of a brush stroke, the noise decides where the edge falls and the contrast sharpens it. Because the noise comes from world position rather than UVs, the edge carries on across the join between two meshes, the same as the texture.

The MLB_GroundBlend graph in Unreal: a vertex colour channel, optionally inverted, is doubled and added to a noise texture sampled from absolute world position, then saturated and put through a cheap contrast node to drive the alpha of a Blend Material Attributes node between a bottom and a top layer
MLB_GroundBlend, with the noise and contrast feeding the blend alpha.
Blend’s parameters

MLB_GroundBlend

Control
Noise

ML_GroundLayer

Material scale
Same as Opaque
  • float
  • bool
  • texture
  • channel
The blend and layer settings.

Decal

I wrote the Decals slide of the art bible, which planned graffiti, cracks, grunge and markings to break up the trim sheets.

An art bible slide titled Decals. The text says graffiti, cracks, grunge and markings decals break up trim sheets and add fine detail. Around it are Borderlands 3 screenshots of wall graffiti, painted floor markings, cracked concrete and grunge stains, labelled Markings, Graffiti, Cracks and Grunge.
My Decals slide from the art bible.

In the Decal master, every channel has its own switch, and atlas controls let one texture sheet hold several decals packed to save VRAM, picked by column, row and index.

To really nail the painted look, the decals had to be hand-drawn, as this is a very distinct aspect when looking at the game. References were gathered from various places that we could use, like Unreal’s Starter Content or Megascans leakages, and then manually remade by Milly and Ollie. The effort paid off.

Optimisation

All master materials made use of static switches, so that unused features would not add to performance cost. Packed textures avoided higher texture usage. Since these materials were used on almost every asset in the game, I kept the shader complexity as low as possible.

Assets were also optimised: set to be immovable and use Nanite to benefit from batch instancing, with harsh Levels of Detail (LODs) for assets that couldn’t support Nanite, like the translucent holograms or the material blend floors.

Part of the level from above in the LOD colouration view mode, with walls and props tinted green, blue and red by LOD level against the untinted scene
Traditional LODs where Nanite couldn't be used.
The level from above in the Nanite mask view, most of the buildings and the highway in green and the roads and pavements in red
Nanite mask. Green is Nanite.
The shader complexity view over part of the track, most of the scene dark green with large areas of red along the ground
Shader complexity.

Reflections

Using Nanite probably did more harm than good, as the game had to do rendering for both pipelines. Traditional LODs would have sufficed. I also didn’t do much profiling outside of stat GPU and the shader complexity view, so I had no repeatable numbers to show where the biggest costs were or whether my changes helped. I also juggled this amongst a lot of other areas of work, so I couldn’t give it the focus it deserved.