/** * @file class1\deferred\pbrterrainUtilF.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 * $/LicenseInfo$ */ /*[EXTRA_CODE_HERE]*/ /** * Triplanar mapping implementation adapted from Inigo Quilez' example shader, * MIT license. * https://www.shadertoy.com/view/MtsGWH * Copyright © 2015 Inigo Quilez * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to * deal in the Software without restriction, including without limitation the * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or * sell copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: The above copyright * notice and this permission notice shall be included in all copies or * substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", * WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #define TERRAIN_PBR_DETAIL_EMISSIVE 0 #define TERRAIN_PBR_DETAIL_OCCLUSION -1 #define TERRAIN_PBR_DETAIL_NORMAL -2 #define TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS -3 in vec3 vary_vertex_normal; vec3 srgb_to_linear(vec3 c); // A relatively agressive threshold for terrain material mixing sampling // cutoff. This ensures that only one or two materials are used in most places, // making PBR terrain blending more performant. Should be greater than 0 to work. #define TERRAIN_RAMP_MIX_THRESHOLD 0.1 // A small threshold for triplanar mapping sampling cutoff. This and // TERRAIN_TRIPLANAR_BLEND_FACTOR together ensures that only one or two samples // per texture are used in most places, making triplanar mapping more // performant. Should be greater than 0 to work. // There's also an artistic design choice in the use of these factors, and the // use of triplanar generally. Don't take these triplanar constants for granted. #define TERRAIN_TRIPLANAR_MIX_THRESHOLD 0.01 #define SAMPLE_X 1 << 0 #define SAMPLE_Y 1 << 1 #define SAMPLE_Z 1 << 2 #define MIX_X 1 << 3 #define MIX_Y 1 << 4 #define MIX_Z 1 << 5 #define MIX_W 1 << 6 struct PBRMix { vec4 col; // RGB color with alpha, linear space #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION) vec3 orm; // Occlusion, roughness, metallic #elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS) vec2 rm; // Roughness, metallic #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL) vec3 vNt; // Unpacked normal texture sample, vector #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE) vec3 emissive; // RGB emissive color, linear space #endif }; PBRMix init_pbr_mix() { PBRMix mix; mix.col = vec4(0); #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION) mix.orm = vec3(0); #elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS) mix.rm = vec2(0); #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL) mix.vNt = vec3(0); #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE) mix.emissive = vec3(0); #endif return mix; } // Usage example, for two weights: // vec2 weights = ... // Weights must add up to 1 // PBRMix mix = init_pbr_mix(); // PBRMix mix1 = ... // mix = mix_pbr(mix, mix1, weights.x); // PBRMix mix2 = ... // mix = mix_pbr(mix, mix2, weights.y); PBRMix mix_pbr(PBRMix mix1, PBRMix mix2, float mix2_weight) { PBRMix mix; mix.col = mix1.col + (mix2.col * mix2_weight); #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION) mix.orm = mix1.orm + (mix2.orm * mix2_weight); #elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS) mix.rm = mix1.rm + (mix2.rm * mix2_weight); #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL) mix.vNt = mix1.vNt + (mix2.vNt * mix2_weight); #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE) mix.emissive = mix1.emissive + (mix2.emissive * mix2_weight); #endif return mix; } PBRMix sample_pbr( vec2 uv , sampler2D tex_col #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS) , sampler2D tex_orm #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL) , sampler2D tex_vNt #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE) , sampler2D tex_emissive #endif ) { PBRMix mix; mix.col = texture(tex_col, uv); mix.col.rgb = srgb_to_linear(mix.col.rgb); #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION) mix.orm = texture(tex_orm, uv).xyz; #elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS) mix.rm = texture(tex_orm, uv).yz; #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL) mix.vNt = texture(tex_vNt, uv).xyz*2.0-1.0; #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE) mix.emissive = srgb_to_linear(texture(tex_emissive, uv).xyz); #endif return mix; } struct TerrainTriplanar { vec3 weight; int type; }; struct TerrainMix { vec4 weight; int type; }; #define TerrainMixSample vec4[4] #define TerrainMixSample3 vec3[4] TerrainMix get_terrain_mix_weights(float alpha1, float alpha2, float alphaFinal) { TerrainMix tm; vec4 sample_x = vec4(1,0,0,0); vec4 sample_y = vec4(0,1,0,0); vec4 sample_z = vec4(0,0,1,0); vec4 sample_w = vec4(0,0,0,1); tm.weight = mix( mix(sample_w, sample_z, alpha2), mix(sample_y, sample_x, alpha1), alphaFinal ); tm.weight -= TERRAIN_RAMP_MIX_THRESHOLD; ivec4 usage = max(ivec4(0), ivec4(ceil(tm.weight))); // Prevent negative weights and keep weights balanced tm.weight = tm.weight*vec4(usage); tm.weight /= (tm.weight.x + tm.weight.y + tm.weight.z + tm.weight.w); tm.type = (usage.x * MIX_X) | (usage.y * MIX_Y) | (usage.z * MIX_Z) | (usage.w * MIX_W); return tm; } TerrainTriplanar _t_triplanar() { float sharpness = TERRAIN_TRIPLANAR_BLEND_FACTOR; float threshold = TERRAIN_TRIPLANAR_MIX_THRESHOLD; vec3 weight_signed = pow(abs(vary_vertex_normal), vec3(sharpness)); weight_signed /= (weight_signed.x + weight_signed.y + weight_signed.z); weight_signed -= vec3(threshold); TerrainTriplanar tw; // *NOTE: Make sure the threshold doesn't affect the materials tw.weight = max(vec3(0), weight_signed); tw.weight /= (tw.weight.x + tw.weight.y + tw.weight.z); ivec3 usage = ivec3(round(max(vec3(0), sign(weight_signed)))); tw.type = ((usage.x) * SAMPLE_X) | ((usage.y) * SAMPLE_Y) | ((usage.z) * SAMPLE_Z); return tw; } // Assume weights add to 1 float terrain_mix(TerrainMix tm, vec4 tms4) { return (tm.weight.x * tms4[0]) + (tm.weight.y * tms4[1]) + (tm.weight.z * tms4[2]) + (tm.weight.w * tms4[3]); } #if TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT == 3 // Triplanar mapping // Pre-transformed texture coordinates for each axial uv slice (Packing: xy, yz, (-x)z, unused) #define TerrainCoord vec4[3] // If sign_or_zero is positive, use uv_unflippped, otherwise use uv_flipped vec2 _t_uv(vec2 uv_unflipped, vec2 uv_flipped, float sign_or_zero) { return mix(uv_flipped, uv_unflipped, max(0.0, sign_or_zero)); } vec3 _t_normal_post_1(vec3 vNt0, float sign_or_zero) { // Assume normal is unpacked vec3 vNt1 = vNt0; // Get sign float sign = sign_or_zero; // Handle case where sign is 0 sign = (2.0*sign) + 1.0; sign /= abs(sign); // If the sign is negative, rotate normal by 180 degrees vNt1.xy = (min(0, sign) * vNt1.xy) + (min(0, -sign) * -vNt1.xy); return vNt1; } // Triplanar-specific normal texture fixes 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) { vec3 vNt_y = _t_normal_post_1(vNt0, sign(vary_vertex_normal.y)); // *HACK: Transform normals according to orientation of the UVs vNt_y.xy = -vNt_y.xy; return vNt_y; } vec3 _t_normal_post_z(vec3 vNt0) { vec3 vNt_z = _t_normal_post_1(vNt0, sign(vary_vertex_normal.z)); return vNt_z; } PBRMix terrain_sample_pbr( TerrainCoord terrain_coord , TerrainTriplanar tw , sampler2D tex_col #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS) , sampler2D tex_orm #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 #endif ) { PBRMix mix = init_pbr_mix(); #define get_uv_x() _t_uv(terrain_coord[0].zw, terrain_coord[1].zw, sign(vary_vertex_normal.x)) #define get_uv_y() _t_uv(terrain_coord[1].xy, terrain_coord[2].xy, sign(vary_vertex_normal.y)) #define get_uv_z() _t_uv(terrain_coord[0].xy, vec2(0), sign(vary_vertex_normal.z)) switch (tw.type & SAMPLE_X) { case SAMPLE_X: PBRMix mix_x = sample_pbr( get_uv_x() , tex_col #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS) , tex_orm #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL) , tex_vNt #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE) , tex_emissive #endif ); #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL) // Triplanar-specific normal texture fix mix_x.vNt = _t_normal_post_x(mix_x.vNt, tangent_sign); #endif mix = mix_pbr(mix, mix_x, tw.weight.x); break; default: break; } switch (tw.type & SAMPLE_Y) { case SAMPLE_Y: PBRMix mix_y = sample_pbr( get_uv_y() , tex_col #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS) , tex_orm #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL) , tex_vNt #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE) , tex_emissive #endif ); #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL) // Triplanar-specific normal texture fix mix_y.vNt = _t_normal_post_y(mix_y.vNt); #endif mix = mix_pbr(mix, mix_y, tw.weight.y); break; default: break; } switch (tw.type & SAMPLE_Z) { case SAMPLE_Z: PBRMix mix_z = sample_pbr( get_uv_z() , tex_col #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS) , tex_orm #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL) , tex_vNt #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE) , tex_emissive #endif ); #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_NORMAL) // Triplanar-specific normal texture fix // *NOTE: Bottom face has not been tested mix_z.vNt = _t_normal_post_z(mix_z.vNt); #endif mix = mix_pbr(mix, mix_z, tw.weight.z); break; default: break; } return mix; } #elif TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT == 1 #define TerrainCoord vec2 #define terrain_sample_pbr sample_pbr #endif PBRMix multiply_factors_pbr( PBRMix mix_in , vec4 factor_col #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION) , vec3 factor_orm #elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS) , vec2 factor_rm #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE) , vec3 factor_emissive #endif ) { PBRMix mix = mix_in; mix.col *= factor_col; #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION) mix.orm *= factor_orm; #elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS) mix.rm *= factor_rm; #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE) mix.emissive *= factor_emissive; #endif return mix; } PBRMix terrain_sample_and_multiply_pbr( TerrainCoord terrain_coord , sampler2D tex_col #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS) , sampler2D tex_orm #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 #endif , vec4 factor_col #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION) , vec3 factor_orm #elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS) , vec2 factor_rm #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE) , vec3 factor_emissive #endif ) { PBRMix mix = terrain_sample_pbr( terrain_coord #if TERRAIN_PLANAR_TEXTURE_SAMPLE_COUNT == 3 , _t_triplanar() #endif , tex_col #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS) , tex_orm #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 #endif ); mix = multiply_factors_pbr(mix , factor_col #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_OCCLUSION) , factor_orm #elif (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_METALLIC_ROUGHNESS) , factor_rm #endif #if (TERRAIN_PBR_DETAIL >= TERRAIN_PBR_DETAIL_EMISSIVE) , factor_emissive #endif ); return mix; }