EG/RenderPipelineFile/rpplugins/ao/shader/alchemy.kernel.glsl
2025-07-24 11:37:46 +08:00

72 lines
2.2 KiB
GLSL

/**
*
* RenderPipeline
*
* Copyright (c) 2014-2016 tobspr <tobias.springer1@gmail.com>
*
* 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.
*
*/
/*
ALCHEMY AO
Projects random points to screen space, and uses the average unoccluded vector
to approximate AO.
*/
const float sample_radius = GET_SETTING(ao, alchemy_sample_radius);
float max_dist = GET_SETTING(ao, alchemy_max_distance);
float accum = 0.0;
int accum_count = 0;
vec2 offset_scale = pixel_size * sample_radius * kernel_scale * 0.5;
START_ITERATE_SEQUENCE(ao, alchemy_sequence, vec2 offset)
offset = mix(offset, noise_vec.xy, 0.3);
vec2 offcoord = texcoord + offset * offset_scale;
// Get view position at that offset
vec3 off_pos = get_view_pos_at(offcoord);
// Get the vector s-p to that sample position
vec3 sample_vec = normalize(off_pos - pixel_view_pos);
// Check if the distance matches, discard matches which are too far away
float dist = distance(off_pos, pixel_view_pos) / max_dist;
if (dist < 1.0) {
// Weight sample by the angle
accum += max(0, dot(pixel_view_normal, sample_vec)) * (1-dist);
}
++accum_count;
END_ITERATE_SEQUENCE();
// Normalize values
accum /= max(1.0, float(accum_count));
result = 1 - accum;