Shader Complexity
Viewport view of per-pixel material cost
Also known as: Shader Complexity view mode · Material instruction count · Optimization viewmodes
Definition
Shader Complexity is an Unreal Engine view mode that colors each pixel by the cost of the material shading it, running from green for cheap through red to white for very expensive. It helps artists find materials that are too heavy and stacked translucent surfaces that cost more because several layers are shaded per pixel. You open it from the viewport's View Mode menu, under Optimization Viewmodes.
In production
Check it early in each environment: look for red or white areas on foliage, glass, particles and layered materials, then simplify the material, reduce translucency or switch to Masked. Judge it in a lit, representative scene rather than an empty level, and compare it with real frame cost from profiling tools, since the color alone does not give you frame time.
Tools that use Shader Complexity
See also
Overdraw
Redrawing same pixels
Draw Call
GPU rendering command
Master Material
Parent material that spawns instances
Blend Mode
How a material combines with what is behind it
Polycount
Triangle budget for a mesh
Profiling
Measure before you optimize
Vertex and Pixel Shaders
The two main GPU programs in every material
Fill Rate
How many pixels the GPU can shade per second