diff options
Diffstat (limited to 'indra/newview/app_settings/shaders/class1/deferred/textureUtilV.glsl')
| -rw-r--r-- | indra/newview/app_settings/shaders/class1/deferred/textureUtilV.glsl | 87 |
1 files changed, 57 insertions, 30 deletions
diff --git a/indra/newview/app_settings/shaders/class1/deferred/textureUtilV.glsl b/indra/newview/app_settings/shaders/class1/deferred/textureUtilV.glsl index 7c02cb9d4a..c75a0e0d5d 100644 --- a/indra/newview/app_settings/shaders/class1/deferred/textureUtilV.glsl +++ b/indra/newview/app_settings/shaders/class1/deferred/textureUtilV.glsl @@ -1,24 +1,24 @@ -/** +/** * @file class1/deferred/textureUtilV.glsl * * $LicenseInfo:firstyear=2023&license=viewerlgpl$ * Second Life Viewer Source Code * Copyright (C) 2023, Linden Research, Inc. - * + * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; * version 2.1 of the License only. - * + * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. - * + * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA - * + * * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA * $/LicenseInfo$ */ @@ -48,6 +48,7 @@ vec2 khr_texture_transform(vec2 texcoord, vec2 scale, float rotation, vec2 offse return (transform * vec3(texcoord, 1)).xy; } +// A texture transform function for PBR materials applied to shape prims/Collada model prims // vertex_texcoord - The UV texture coordinates sampled from the vertex at // runtime. Per SL convention, this is in a right-handed UV coordinate // system. Collada models also have right-handed UVs. @@ -93,36 +94,48 @@ vec2 terrain_texture_transform(vec2 vertex_texcoord, vec4[2] khr_gltf_transform) // Take the rotation only from both transforms and apply to the tangent. This // accounts for the change of the topology of the normal texture when a texture // rotation is applied to it. +// In practice, this applies the inverse of the texture transform to the tangent. +// It is effectively an inverse of the rotation // *HACK: Assume the imported GLTF model did not have both normal texture // transforms and tangent vertices. The use of this function is inconsistent // with the GLTF sample viewer when that is the case. See getNormalInfo in // https://raw.githubusercontent.com/KhronosGroup/glTF-Sample-Viewer/47a191931461a6f2e14de48d6da0f0eb6ec2d147/source/Renderer/shaders/material_info.glsl // We may want to account for this case during GLTF model import. // -Cosmic,2023-06-06 -vec3 tangent_space_transform(vec4 vertex_tangent, vec3 vertex_normal, vec4[2] khr_gltf_transform, mat4 sl_animation_transform) +vec4 tangent_space_transform(vec4 vertex_tangent, vec3 vertex_normal, vec4[2] khr_gltf_transform, mat4 sl_animation_transform) { - vec2 weights = vec2(0, 1); - - // Apply texture animation first to avoid shearing and other artifacts (rotation only) - mat2 sl_rot_scale; - sl_rot_scale[0][0] = sl_animation_transform[0][0]; - sl_rot_scale[0][1] = sl_animation_transform[0][1]; - sl_rot_scale[1][0] = sl_animation_transform[1][0]; - sl_rot_scale[1][1] = sl_animation_transform[1][1]; - weights = sl_rot_scale * weights; - // Remove scale - weights = normalize(weights); + // Immediately convert to left-handed coordinate system, but it has no + // effect here because y is 0 ((1,0) -> (1,0)) + vec2 weights = vec2(1, 0); - // Convert to left-handed coordinate system - weights.y = -weights.y; - - // Apply KHR_texture_transform (rotation only) - float khr_rotation = khr_gltf_transform[0].z; + // Apply inverse KHR_texture_transform (rotation and scale sign only) + float khr_rotation = -khr_gltf_transform[0].z; mat2 khr_rotation_mat = mat2( cos(khr_rotation),-sin(khr_rotation), sin(khr_rotation), cos(khr_rotation) ); weights = khr_rotation_mat * weights; + vec2 khr_scale_sign = sign(khr_gltf_transform[0].xy); + weights *= khr_scale_sign.xy; + + // *NOTE: Delay conversion to right-handed coordinate system here, to + // remove the need for computing the inverse of the SL texture animation + // matrix. + + // Apply texture animation last to avoid shearing and other artifacts (rotation only) + mat2 inv_sl_rot_scale; + inv_sl_rot_scale[0][0] = sl_animation_transform[0][0]; + inv_sl_rot_scale[0][1] = sl_animation_transform[0][1]; + inv_sl_rot_scale[1][0] = sl_animation_transform[1][0]; + inv_sl_rot_scale[1][1] = sl_animation_transform[1][1]; + weights = inv_sl_rot_scale * weights; + // *NOTE: Scale to be removed later + + // Set weights to default if 0 for some reason + weights.x += 1.0 - abs(sign(sign(weights.x) + (0.5 * sign(weights.y)))); + + // Remove scale from SL texture animation transform + weights = normalize(weights); // Convert back to right-handed coordinate system weights.y = -weights.y; @@ -131,27 +144,41 @@ vec3 tangent_space_transform(vec4 vertex_tangent, vec3 vertex_normal, vec4[2] kh // from the normal and tangent, as seen in the fragment shader vec3 vertex_binormal = vertex_tangent.w * cross(vertex_normal, vertex_tangent.xyz); - return (weights.x * vertex_binormal.xyz) + (weights.y * vertex_tangent.xyz); + // An additional sign flip prevents the binormal from being flipped as a + // result of a propagation of the tangent sign during the cross product. + float sign_flip = khr_scale_sign.x * khr_scale_sign.y; + return vec4((weights.x * vertex_tangent.xyz) + (weights.y * vertex_binormal.xyz), vertex_tangent.w * sign_flip); } -// Similar to tangent_space_transform but no no texture animation support. -vec3 terrain_tangent_space_transform(vec4 vertex_tangent, vec3 vertex_normal, vec4[2] khr_gltf_transform) +// Similar to tangent_space_transform but no texture animation support. +vec4 terrain_tangent_space_transform(vec4 vertex_tangent, vec3 vertex_normal, vec4[2] khr_gltf_transform) { - // Immediately convert to left-handed coordinate system ((0,1) -> (0, -1)) - vec2 weights = vec2(0, -1); + // Immediately convert to left-handed coordinate system, but it has no + // effect here because y is 0 ((1,0) -> (1,0)) + vec2 weights = vec2(1, 0); - // Apply KHR_texture_transform (rotation only) - float khr_rotation = khr_gltf_transform[0].z; + // Apply inverse KHR_texture_transform (rotation and scale sign only) + float khr_rotation = -khr_gltf_transform[0].z; mat2 khr_rotation_mat = mat2( cos(khr_rotation),-sin(khr_rotation), sin(khr_rotation), cos(khr_rotation) ); weights = khr_rotation_mat * weights; + vec2 khr_scale_sign = sign(khr_gltf_transform[0].xy); + weights *= khr_scale_sign.xy; + + // Set weights to default if 0 for some reason + weights.x += 1.0 - abs(sign(sign(weights.x) + (0.5 * sign(weights.y)))); // Convert back to right-handed coordinate system weights.y = -weights.y; + // Similar to the MikkTSpace-compatible method of extracting the binormal + // from the normal and tangent, as seen in the fragment shader vec3 vertex_binormal = vertex_tangent.w * cross(vertex_normal, vertex_tangent.xyz); - return (weights.x * vertex_binormal.xyz) + (weights.y * vertex_tangent.xyz); + // An additional sign flip prevents the binormal from being flipped as a + // result of a propagation of the tangent sign during the cross product. + float sign_flip = khr_scale_sign.x * khr_scale_sign.y; + return vec4((weights.x * vertex_tangent.xyz) + (weights.y * vertex_binormal.xyz), vertex_tangent.w * sign_flip); } |