forked from Rowland/EG
93 lines
3.2 KiB
GLSL
93 lines
3.2 KiB
GLSL
/**
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*
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* RenderPipeline
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*
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* Copyright (c) 2014-2016 tobspr <tobias.springer1@gmail.com>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*
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*/
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#pragma once
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// Required inputs
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uniform sampler3D SceneVoxels;
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uniform samplerCube ScatteringIBLSpecular;
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uniform samplerCube ScatteringIBLDiffuse;
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// Voxel grid parameters
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uniform vec3 voxelGridPosition;
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uniform float voxelGridSize;
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uniform int voxelGridResolution;
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vec3 worldspace_to_voxelspace(vec3 worldspace) {
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vec3 voxel_coord = (worldspace - voxelGridPosition) / GET_SETTING(vxgi, grid_ws_size);
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return fma(voxel_coord, vec3(0.5), vec3(0.5));
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}
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float get_mipmap_from_cone_radius(float cone_radius) {
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return log2(cone_radius * GET_SETTING(vxgi, grid_resolution) * 0.6) - 1;
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}
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vec4 trace_cone(vec3 start_pos, vec3 nrm, vec3 direction, int max_steps,
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bool is_specular, float cone_grow_factor, float seed) {
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// Find initial cone radius
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float cone_radius = (1.0 + 5.0 * cone_grow_factor) / GET_SETTING(vxgi, grid_resolution);
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// Offset start position to avoid self intersection
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start_pos += nrm * 1.5 / GET_SETTING(vxgi, grid_resolution);
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start_pos += direction * 5.5 / GET_SETTING(vxgi, grid_resolution);
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if (!is_specular) {
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// start_pos += nrm * 1.5 / GET_SETTING(vxgi, grid_resolution);
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}
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// Cone parameters
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vec3 current_pos = start_pos;
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vec4 accum = vec4(0);
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float mipmap = 0.0;
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current_pos += direction * cone_radius * seed;
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// Trace the cone over the voxel grid
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for (int i = 0; i < max_steps; ++i) {
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mipmap = get_mipmap_from_cone_radius(cone_radius);
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vec4 sampled = textureLod(SceneVoxels, current_pos, mipmap);
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sampled.w *= 2.0;
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sampled.w = saturate(sampled.w);
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accum += sampled * (1.0 - accum.w);
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current_pos += direction * cone_radius / 2.25;
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cone_radius *= 1.01 + cone_grow_factor;
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}
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// Unpack packed color, since we use 8 bit targets only
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accum.xyz = accum.xyz / (1 - accum.xyz);
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// accum.xyz *= 15.0;
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if (is_specular) {
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// accum.xyz += textureLod(ScatteringIBLSpecular, direction, mipmap).xyz * (1-accum.w);
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} else {
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// accum.xyz += textureLod(ScatteringIBLDiffuse, direction, 0).xyz * (1-accum.w) * 0.1;
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}
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return accum;
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}
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