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Merge pull request #1882 from secondlife/v-1847 

secondlife/viewer#1847: Fix negative UV scale inverting normal texture lighting for PBR materials and PBR terrain
master
cosmic-linden 2024-07-01 14:52:58 -07:00 committed by GitHub
parent 817a1321db 186395ee4b
commit e32f6426d5
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GPG Key ID: B5690EEEBB952194
7 changed files with 116 additions and 47 deletions
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11
doc/testplans/pbr_terrain_appearance.md
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@ -50,3 +50,14 @@ If triplanar mapping is enabled, and an avatar faces an axially-aligned wall, th
Textures of materials should not appear mirrored.
When triplanar mapping is enabled, rotations on the axially aligned walls should apply in the same direction as they would on flat ground.
## PBR Terrain Normal Textures
This section assumes terrain normal maps are enabled at the current graphics setting.
PBR terrain should have approximately correct lighting based on the normal texture:
- When on flat ground
- On cliffs, when triplanar mapping is enabled. Lighting will be somewhat less accurate when the cliff face is not axially aligned.
- If no Terrain Texture Transform is applied.
- If a Terrain Texture Transform is applied, especially for rotation or negative scale.

7
indra/newview/app_settings/shaders/class1/deferred/pbralphaV.glsl
View File

@ -69,7 +69,7 @@ flat out float vary_sign;
out vec3 vary_normal;
vec2 texture_transform(vec2 vertex_texcoord, vec4[2] khr_gltf_transform, mat4 sl_animation_transform);
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);
void main()
@ -103,8 +103,9 @@ void main()
n = normalize(n);
vary_tangent = normalize(tangent_space_transform(vec4(t, tangent.w), n, texture_normal_transform, texture_matrix0));
vary_sign = tangent.w;
vec4 transformed_tangent = tangent_space_transform(vec4(t, tangent.w), n, texture_normal_transform, texture_matrix0);
vary_tangent = normalize(transformed_tangent.xyz);
vary_sign = transformed_tangent.w;
vary_normal = n;
vertex_color = diffuse_color;

7
indra/newview/app_settings/shaders/class1/deferred/pbropaqueV.glsl
View File

@ -63,7 +63,7 @@ out vec3 vary_normal;
out vec3 vary_position;
vec2 texture_transform(vec2 vertex_texcoord, vec4[2] khr_gltf_transform, mat4 sl_animation_transform);
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);
void main()
{
@ -97,8 +97,9 @@ void main()
n = normalize(n);
vary_tangent = normalize(tangent_space_transform(vec4(t, tangent.w), n, texture_normal_transform, texture_matrix0));
vary_sign = tangent.w;
vec4 transformed_tangent = tangent_space_transform(vec4(t, tangent.w), n, texture_normal_transform, texture_matrix0);
vary_tangent = normalize(transformed_tangent.xyz);
vary_sign = transformed_tangent.w;
vary_normal = n;
vertex_color = diffuse_color;

29
indra/newview/app_settings/shaders/class1/deferred/pbrterrainF.glsl
View File

@ -75,6 +75,9 @@ PBRMix terrain_sample_and_multiply_pbr(
#endif
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
, sampler2D tex_vNt
#if TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT == 3
, float transform_sign
#endif
#endif
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
, sampler2D tex_emissive
@ -139,7 +142,7 @@ in vec3 vary_position;
in vec3 vary_normal;
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
in vec3 vary_tangents[4];
flat in float vary_sign;
flat in float vary_signs[4];
#endif
in vec4 vary_texcoord0;
in vec4 vary_texcoord1;
@ -150,11 +153,11 @@ float terrain_mix(TerrainMix tm, vec4 tms4);
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
// from mikktspace.com
vec3 mikktspace(vec3 vNt, vec3 vT)
vec3 mikktspace(vec3 vNt, vec3 vT, float sign)
{
vec3 vN = vary_normal;
vec3 vB = vary_sign * cross(vN, vT);
vec3 vB = sign * cross(vN, vT);
vec3 tnorm = normalize( vNt.x * vT + vNt.y * vB + vNt.z * vN );
tnorm *= gl_FrontFacing ? 1.0 : -1.0;
@ -216,6 +219,9 @@ void main()
#endif
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
, detail_0_normal
#if TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT == 3
, vary_signs[0]
#endif
#endif
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
, detail_0_emissive
@ -231,7 +237,7 @@ void main()
#endif
);
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
mix2.vNt = mikktspace(mix2.vNt, vary_tangents[0]);
mix2.vNt = mikktspace(mix2.vNt, vary_tangents[0], vary_signs[0]);
#endif
pbr_mix = mix_pbr(pbr_mix, mix2, tm.weight.x);
break;
@ -258,6 +264,9 @@ void main()
#endif
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
, detail_1_normal
#if TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT == 3
, vary_signs[1]
#endif
#endif
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
, detail_1_emissive
@ -273,7 +282,7 @@ void main()
#endif
);
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
mix2.vNt = mikktspace(mix2.vNt, vary_tangents[1]);
mix2.vNt = mikktspace(mix2.vNt, vary_tangents[1], vary_signs[1]);
#endif
pbr_mix = mix_pbr(pbr_mix, mix2, tm.weight.y);
break;
@ -300,6 +309,9 @@ void main()
#endif
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
, detail_2_normal
#if TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT == 3
, vary_signs[2]
#endif
#endif
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
, detail_2_emissive
@ -315,7 +327,7 @@ void main()
#endif
);
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
mix2.vNt = mikktspace(mix2.vNt, vary_tangents[2]);
mix2.vNt = mikktspace(mix2.vNt, vary_tangents[2], vary_signs[2]);
#endif
pbr_mix = mix_pbr(pbr_mix, mix2, tm.weight.z);
break;
@ -342,6 +354,9 @@ void main()
#endif
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
, detail_3_normal
#if TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT == 3
, vary_signs[3]
#endif
#endif
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
, detail_3_emissive
@ -357,7 +372,7 @@ void main()
#endif
);
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
mix2.vNt = mikktspace(mix2.vNt, vary_tangents[3]);
mix2.vNt = mikktspace(mix2.vNt, vary_tangents[3], vary_signs[3]);
#endif
pbr_mix = mix_pbr(pbr_mix, mix2, tm.weight.w);
break;

12
indra/newview/app_settings/shaders/class1/deferred/pbrterrainUtilF.glsl
View File

@ -256,11 +256,12 @@ vec3 _t_normal_post_1(vec3 vNt0, float sign_or_zero)
}
// Triplanar-specific normal texture fixes
vec3 _t_normal_post_x(vec3 vNt0)
vec3 _t_normal_post_x(vec3 vNt0, float tangent_sign)
{
vec3 vNt_x = _t_normal_post_1(vNt0, sign(vary_vertex_normal.x));
// *HACK: Transform normals according to orientation of the UVs
vNt_x.xy = vec2(-vNt_x.y, vNt_x.x);
vNt_x.xy *= tangent_sign;
return vNt_x;
}
vec3 _t_normal_post_y(vec3 vNt0)
@ -285,6 +286,7 @@ PBRMix terrain_sample_pbr(
#endif
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
, sampler2D tex_vNt
, float tangent_sign
#endif
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
, sampler2D tex_emissive
@ -314,7 +316,7 @@ PBRMix terrain_sample_pbr(
);
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
// Triplanar-specific normal texture fix
mix_x.vNt = _t_normal_post_x(mix_x.vNt);
mix_x.vNt = _t_normal_post_x(mix_x.vNt, tangent_sign);
#endif
mix = mix_pbr(mix, mix_x, tw.weight.x);
break;
@ -420,6 +422,9 @@ PBRMix terrain_sample_and_multiply_pbr(
#endif
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
, sampler2D tex_vNt
#if TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT == 3
, float tangent_sign
#endif
#endif
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
, sampler2D tex_emissive
@ -446,6 +451,9 @@ PBRMix terrain_sample_and_multiply_pbr(
#endif
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
, tex_vNt
#if TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT == 3
, tangent_sign
#endif
#endif
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE)
, tex_emissive

23
indra/newview/app_settings/shaders/class1/deferred/pbrterrainV.glsl
View File

@ -43,7 +43,7 @@ out vec3 vary_vertex_normal; // Used by pbrterrainUtilF.glsl
out vec3 vary_normal;
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
out vec3 vary_tangents[4];
flat out float vary_sign;
flat out float vary_signs[4];
#endif
out vec4 vary_texcoord0;
out vec4 vary_texcoord1;
@ -60,7 +60,7 @@ out vec3 vary_position;
uniform vec4[5] terrain_texture_transforms;
vec2 terrain_texture_transform(vec2 vertex_texcoord, vec4[2] khr_gltf_transform);
vec3 terrain_tangent_space_transform(vec4 vertex_tangent, vec3 vertex_normal, vec4[2] khr_gltf_transform);
vec4 terrain_tangent_space_transform(vec4 vertex_tangent, vec3 vertex_normal, vec4[2] khr_gltf_transform);
void main()
{
@ -75,28 +75,35 @@ void main()
#if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL)
{
vec4[2] ttt;
vec4 transformed_tangent;
// material 1
ttt[0].xyz = terrain_texture_transforms[0].xyz;
ttt[1].x = terrain_texture_transforms[0].w;
ttt[1].y = terrain_texture_transforms[1].x;
vary_tangents[0] = normalize(terrain_tangent_space_transform(vec4(t, tangent.w), n, ttt));
transformed_tangent = terrain_tangent_space_transform(vec4(t, tangent.w), n, ttt);
vary_tangents[0] = normalize(transformed_tangent.xyz);
vary_signs[0] = transformed_tangent.w;
// material 2
ttt[0].xyz = terrain_texture_transforms[1].yzw;
ttt[1].xy = terrain_texture_transforms[2].xy;
vary_tangents[1] = normalize(terrain_tangent_space_transform(vec4(t, tangent.w), n, ttt));
transformed_tangent = terrain_tangent_space_transform(vec4(t, tangent.w), n, ttt);
vary_tangents[1] = normalize(transformed_tangent.xyz);
vary_signs[1] = transformed_tangent.w;
// material 3
ttt[0].xy = terrain_texture_transforms[2].zw;
ttt[0].z = terrain_texture_transforms[3].x;
ttt[1].xy = terrain_texture_transforms[3].yz;
vary_tangents[2] = normalize(terrain_tangent_space_transform(vec4(t, tangent.w), n, ttt));
transformed_tangent = terrain_tangent_space_transform(vec4(t, tangent.w), n, ttt);
vary_tangents[2] = normalize(transformed_tangent.xyz);
vary_signs[2] = transformed_tangent.w;
// material 4
ttt[0].x = terrain_texture_transforms[3].w;
ttt[0].yz = terrain_texture_transforms[4].xy;
ttt[1].xy = terrain_texture_transforms[4].zw;
vary_tangents[3] = normalize(terrain_tangent_space_transform(vec4(t, tangent.w), n, ttt));
transformed_tangent = terrain_tangent_space_transform(vec4(t, tangent.w), n, ttt);
vary_tangents[3] = normalize(transformed_tangent.xyz);
vary_signs[3] = transformed_tangent.w;
}
vary_sign = tangent.w;
#endif
vary_normal = normalize(n);

74
indra/newview/app_settings/shaders/class1/deferred/textureUtilV.glsl
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@ -94,36 +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);
// 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 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);
// 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;
@ -132,27 +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 texture animation support.
vec3 terrain_tangent_space_transform(vec4 vertex_tangent, vec3 vertex_normal, vec4[2] khr_gltf_transform)
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);
}