Graphics tools standard shader — MRTK3

The Graphics Tools Standard shading system utilizes a flexible shader that can achieve visuals similar to Unity's Standard (or Lit) shader. It implements Fluent Design System principles and remains performant on mixed reality devices.

Sample

See the Material Gallery sample for multiple demonstrations of Graphics Tools/Standard shader variants. For examples of Graphics Tools/Standard Canvas, see the UnityUI sample

Architecture

The Graphics Tools/Standard shading system is an "uber shader" that uses Unity's shader program variant feature to auto-generate optimal shader code based on material properties. When a user selects material properties in the material inspector, they only incur performance cost for features they've enabled.

To better support traditional Unity workflows and UnityUI (canvas) workflows, the Graphics Tools/Standard shading system has two shader entry points:

Both shaders are mostly identical because they share common shader code includes. The Graphics Tools/Standard Canvas contains some extra logic specific to UnityUI.

The following shader includes power the Graphics Tools/Standard shading system:

Render pipeline support

Unity has a handful of render pipelines for developers to pick from. The Graphics Tools Standard shading system is designed to work automatically with Unity's built-in render pipeline or Universal Render Pipeline(URP). There's no need to switch shaders based on pipeline. Below is a support matrix:

UnityUI support

The Graphics Tools Standard shading system works with Unity's built-in UI system called UnityUI. The Graphics Tools/Standard Canvas should be used for all materials within UnityUI canvases.

A Canvas or CanvasRenderer within Graphics Tools will prompt for the addition of a ScaleMeshEffect.cs when one is required:

On UnityUI components, the unity_ObjectToWorld matrix (or UNITY_MATRIX_M in URP) isn't the transformation matrix of the local transform the Graphic component lives on but that of its parent Canvas. Many Graphics Tools/Standard Canvas shader effects require object scale to be known. To solve this issue, the ScaleMeshEffect.cs will store scaling information into UV channel attributes during UI mesh construction.

Material inspector

A custom material inspector exists for the Graphics Tools/Standard and Graphics Tools/Standard Canvas shaders called StandardShaderGUI.cs. The inspector automatically enables/disables shader features, based on user selection and aides in setting up render state. For more information about each feature hover over each property in the Unity Editor for a tooltip.

The inspector can be broken into a handful of features areas as described below.

Rendering mode

The first portion of the inspector controls the material's render state. Rendering Mode determines when and how a material will be rendered. The aim of the Graphics Tools/Standard and Graphics Tools/Standard Canvas shaders is to mirror the rendering modes found in the Unity/Standard shader. The Graphics Tools/Standard and Graphics Tools/Standard Canvas shaders also include an Additive rendering mode and Custom rendering mode for complete user control.

Cull mode

Main maps

This section's primary function is to control the material's albedo color and physically based rendering options.

To improve parity with the Unity Standard shader per pixel metallic, smoothness, emissive, and occlusion values can all be controlled via channel packing.

When you use channel packing, you only have to sample and load one texture into memory instead of four separate ones. When you write your texture maps in a program like Substance or Photoshop, you can hand pack them like the following:

The main map section also has an option for triplanar mapping and super-sample anti-aliasing. It also contains the option to add colored emission texture maps once the Emission checkbox is selected.

Triplanar mapping is a technique to programmatically texture a mesh. It's often used in terrain, meshes without UVs, or difficult to unwrap shapes. This implementation supports world or local space projection, the specification of blending smoothness, and normal map support. Note, each texture used requires three texture samples, so use sparingly in performance critical situations.

Super-sample anti-aliasing should be used on any materials that display an icon or image where details are critical from a distance.

Rendering options

Rendering options mostly control the lighting settings for a material. This material section also contains a handful of other features that control a surface's color, translucency, or position. For more details about lighting, see below.

Fluent options

Fluent is a design framework used across UI components in Microsoft products. This section contains a handful of features that help emulate Fluent design system principles on arbitrary surfaces. If you're looking for bespoke Fluent shaders, they can be found in the Graphics Tools/Canvas and Graphics Tools/Non-Canvas shader namespace.

Advanced options

Similar to the advanced section in Unity's built-in shaders. This section controls rendering order and if GPU instancing variants should be built. Additionally, there are configurable stencil test supports to achieve a wide array of effects. Such as portals:

Lighting

The Graphics Tools/Standard and Graphics Tools/Standard Canvas shaders use a simple approximation for lighting. Because the shaders don't calculate for physical correctness and energy conservation, they render quickly and efficiently. Blinn-Phong is the primary lighting technique used and is blended with Fresnel and image-based lighting to approximate physically based lighting. The shaders support the following lighting techniques:

Directional light

The shader will respect the direction, color, and intensity of the first Unity Directional Light in the scene (if enabled).

Spherical harmonics

The shader uses light probes to approximate lights in the scene using spherical harmonics, if enabled.

Lightmapping

For static lighting, the shader will respect lightmaps built by Unity's lightmapping system. Mark the renderer as static (or lightmap static) to use lightmaps.

Performance

One of the primary advantages to using the Graphics Tools standard shading system over the Unity Standard shader is performance. The Graphics Tools/Standard and Graphics Tools/Standard Canvas shaders are architected to only utilize the features enabled. However, the Graphics Tools/Standard and Graphics Tools/Standard Canvas shaders have also been written to deliver comparable aesthetic results as the Unity Standard shader, but at a much lower cost. One simple way to compare shader performance is via the number of operations that need to be performed on the GPU. The magnitude of calculations may fluctuate by features enabled and other rendering configurations.

See also

• Hover Light
• Proximity Light
• Clipping Primitive
• Mesh Outlines