84 lines
2.7 KiB
GLSL
84 lines
2.7 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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/*
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CryEngine SSAO - Screen Space Ambient Occlusion
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Samples the depth buffer in a hemisphere arround the current pixel to approximate
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AO.
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*/
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const float sample_radius = GET_SETTING(ao, ssao_sample_radius);
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const float bias = GET_SETTING(ao, ssao_bias) * 0.5 / kernel_scale;
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float max_range = GET_SETTING(ao, ssao_max_distance);
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float sample_offset = sample_radius * pixel_size.x * 30.0;
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float range_accum = 0.0;
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float accum = 0.0;
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// Make sure we have nice sampling coherency by scaling the kernel
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sample_offset /= 0.8 * kernel_scale;
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START_ITERATE_SEQUENCE(ao, ssao_sequence, vec3 offset)
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offset = mix(offset, noise_vec, 0.5);
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offset *= 0.6;
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// Flip offset in case it faces away from the normal
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offset = face_forward(offset, pixel_view_normal);
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// Compute offset position in view space
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vec3 offset_pos = pixel_view_pos + offset * sample_offset;
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// Project offset position to screen space
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vec3 projected = view_to_screen(offset_pos);
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// Fetch the expected depth
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float sample_depth = get_linear_depth_at(projected.xy);
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// Linearize both depths
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float linz_a = get_linear_z_from_z(projected.z);
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float linz_b = sample_depth;
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// Compare both depths by distance to find the AO factor
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float modifier = step(distance(linz_a, linz_b), max_range * 0.2);
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range_accum += fma(modifier, 0.5, 0.5);
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modifier *= step(linz_b + bias, linz_a);
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accum += modifier;
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END_ITERATE_SEQUENCE()
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// normalize samples
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accum /= max(0.1, range_accum);
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// Renormalize to match with the other techniques
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accum *= 0.4;
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result = 1 - accum;
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