This directory contains the GLSL shader source code used by various Escher renderers, along with their compiled SPIR-V outputs.
flatland/: Shaders currently used in production Scenic.
paper/ and model_renderer/: These contain historical shaders originally used for 3D rendering and the legendary PaperRenderer. They are currently preserved because they are still used by several tests.
spirv/: Contains the pre-compiled SPIR-V binaries generated from the GLSL shaders in the directories above, using the paper_shader_compiler host tool.