2 commits

Author	SHA1	Message	Date
Robert Swain	681c9c6dc8	bevy_pbr: Fix tangent and normal normalization (#5666) ... # Objective - Morten Mikkelsen clarified that the world normal and tangent must be normalized in the vertex stage and the interpolated values must not be normalized in the fragment stage. This is in order to match the mikktspace approach exactly. - Fixes #5514 by ensuring the tangent basis matrix (TBN) is orthonormal ## Solution - Normalize the world normal in the vertex stage and not the fragment stage - Normalize the world tangent xyz in the vertex stage - Take into account the sign of the determinant of the local to world matrix when calculating the bitangent --- ## Changelog - Fixed - scaling a model that uses normal mapping now has correct lighting again	2022-08-18 21:54:40 +00:00
Robert Swain	b333386271	Add reusable shader functions for transforming position/normal/tangent (#4901) ... # Objective - Add reusable shader functions for transforming positions / normals / tangents between local and world / clip space for 2D and 3D so that they are done in a simple and correct way - The next step in #3969 so check there for more details. ## Solution - Add `bevy_pbr::mesh_functions` and `bevy_sprite::mesh2d_functions` shader imports - These contain `mesh_` and `mesh2d_` versions of the following functions: - `mesh_position_local_to_world` - `mesh_position_world_to_clip` - `mesh_position_local_to_clip` - `mesh_normal_local_to_world` - `mesh_tangent_local_to_world` - Use them everywhere where it is appropriate - Notably not in the sprite and UI shaders where `mesh2d_position_world_to_clip` could have been used, but including all the functions depends on the mesh binding so I chose to not use the function there - NOTE: The `mesh_` and `mesh2d_` functions are currently identical. However, if I had defined only `bevy_pbr::mesh_functions` and used that in bevy_sprite, then bevy_sprite would have a runtime dependency on bevy_pbr, which seems undesirable. I also expect that when we have a proper 2D rendering API, these functions will diverge between 2D and 3D. --- ## Changelog - Added: `bevy_pbr::mesh_functions` and `bevy_sprite::mesh2d_functions` shader imports containing `mesh_` and `mesh2d_` versions of the following functions: - `mesh_position_local_to_world` - `mesh_position_world_to_clip` - `mesh_position_local_to_clip` - `mesh_normal_local_to_world` - `mesh_tangent_local_to_world` ## Migration Guide - The `skin_tangents` function from the `bevy_pbr::skinning` shader import has been replaced with the `mesh_tangent_local_to_world` function from the `bevy_pbr::mesh_functions` shader import	2022-06-14 00:32:33 +00:00