Developer knowledge network ยท moderated exchange

UnreliableCode Community

Developer Research, Reverse Engineering & Coding Community

Knowledge indexLive
4Categories
919Threads
2.8KPosts
Tutorial

Cascaded Shadow Maps (CSM): Splitting View Frustum for High-Resolution Outdoor Shadows [StackOverflow Architecture Guide]

graphics_pipeline_pro
DirectX / Vulkan Engineer
MEMBER
Rep: 172
Join Date: Sep 2018
Posts: 10
Thanks: 51
1 months ago ยท Jun 26, 2026 10:36 AM
#1

Why standard directional shadow maps look pixelated across large outdoor game environments:

A single $2048\times 2048$ shadow map stretched across an entire 1km landscape gives only ~2mm shadow resolution near the camera, causing blurry pixelated shadows.

Cascaded Shadow Maps (CSM):

  • Split view frustum into 3-4 depth cascades (e.g. 0-15m, 15-60m, 60-250m, 250-1000m).
  • Render separate shadow map tightly bound to each cascade slice.
  • Close-up shadows get crystal-sharp pixel resolution while distant terrain maintains soft coverage!
shader_magician
HLSL / GLSL Dev
MEMBER
Rep: 176
Join Date: Jan 2021
Posts: 8
Thanks: 32
1 months ago ยท Jun 26, 2026 1:25 PM
#2

CSM is standard in open-world titles. Blending between cascade split seams eliminates visual popping.

matrix_math_guy
Math Specialist
MEMBER
Rep: 105
Join Date: Aug 2018
Posts: 52
Thanks: 41
1 months ago ยท Jun 27, 2026 7:04 AM
#3

Using logarithmic depth partitioning provides optimal distribution of shadow map texels.