blender/intern/cycles/render/curves.cpp
Stuart Broadfoot 638b084f82 Cycles Hair: Strand Minimum Pixel Size
Code is added to restrict the pixel size of strands in cycles. It works best with ribbon primitives and a preset for these is included. It uses distance dependent expansion of the strands and then stochastic strand removal to give a fading. To prevent a slowdown for triangle mesh objects in the BVH an extra visibility flag has been added. It is also only applied for camera rays.

The strand width settings are also changed, so that the particle size is not included in the width calculation. Instead there is a separate particle system parameter for width scaling.
2013-04-15 21:38:31 +00:00

217 lines
6.4 KiB
C++

/*
* Copyright 2011, Blender Foundation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include "device.h"
#include "curves.h"
#include "mesh.h"
#include "object.h"
#include "scene.h"
#include "util_foreach.h"
#include "util_map.h"
#include "util_progress.h"
#include "util_vector.h"
CCL_NAMESPACE_BEGIN
/* Curve functions */
void curvebounds(float *lower, float *upper, float3 *p, int dim)
{
float *p0 = &p[0].x;
float *p1 = &p[1].x;
float *p2 = &p[2].x;
float *p3 = &p[3].x;
float fc = 0.71f;
float curve_coef[4];
curve_coef[0] = p1[dim];
curve_coef[1] = -fc*p0[dim] + fc*p2[dim];
curve_coef[2] = 2.0f * fc * p0[dim] + (fc - 3.0f) * p1[dim] + (3.0f - 2.0f * fc) * p2[dim] - fc * p3[dim];
curve_coef[3] = -fc * p0[dim] + (2.0f - fc) * p1[dim] + (fc - 2.0f) * p2[dim] + fc * p3[dim];
float discroot = curve_coef[2] * curve_coef[2] - 3 * curve_coef[3] * curve_coef[1];
float ta = -1.0f;
float tb = -1.0f;
if(discroot >= 0) {
discroot = sqrt(discroot);
ta = (-curve_coef[2] - discroot) / (3 * curve_coef[3]);
tb = (-curve_coef[2] + discroot) / (3 * curve_coef[3]);
ta = (ta > 1.0f || ta < 0.0f) ? -1.0f : ta;
tb = (tb > 1.0f || tb < 0.0f) ? -1.0f : tb;
}
*upper = max(p1[dim],p2[dim]);
*lower = min(p1[dim],p2[dim]);
float exa = p1[dim];
float exb = p2[dim];
float t2;
float t3;
if(ta >= 0.0f) {
t2 = ta * ta;
t3 = t2 * ta;
exa = curve_coef[3] * t3 + curve_coef[2] * t2 + curve_coef[1] * ta + curve_coef[0];
}
if(tb >= 0.0f) {
t2 = tb * tb;
t3 = t2 * tb;
exb = curve_coef[3] * t3 + curve_coef[2] * t2 + curve_coef[1] * tb + curve_coef[0];
}
*upper = max(*upper, max(exa,exb));
*lower = min(*lower, min(exa,exb));
}
/* Hair System Manager */
CurveSystemManager::CurveSystemManager()
{
primitive = CURVE_LINE_SEGMENTS;
line_method = CURVE_CORRECTED;
interpolation = CURVE_CARDINAL;
triangle_method = CURVE_CAMERA_TRIANGLES;
resolution = 3;
segments = 1;
subdivisions = 3;
normalmix = 1.0f;
encasing_ratio = 1.01f;
minimum_width = 0.0f;
maximum_width = 0.0f;
use_curves = true;
use_smooth = true;
use_parents = false;
use_encasing = true;
use_backfacing = false;
use_joined = false;
use_tangent_normal = false;
use_tangent_normal_geometry = false;
use_tangent_normal_correction = false;
need_update = true;
need_mesh_update = false;
}
CurveSystemManager::~CurveSystemManager()
{
}
void CurveSystemManager::device_update(Device *device, DeviceScene *dscene, Scene *scene, Progress& progress)
{
if(!need_update)
return;
device_free(device, dscene);
progress.set_status("Updating Hair settings", "Copying Hair settings to device");
KernelCurves *kcurve= &dscene->data.curve_kernel_data;
kcurve->curveflags = 0;
if(use_curves) {
if(primitive == CURVE_SEGMENTS || primitive == CURVE_RIBBONS)
kcurve->curveflags |= CURVE_KN_INTERPOLATE;
if(primitive == CURVE_RIBBONS)
kcurve->curveflags |= CURVE_KN_RIBBONS;
if(line_method == CURVE_ACCURATE)
kcurve->curveflags |= CURVE_KN_ACCURATE;
if(line_method == CURVE_CORRECTED)
kcurve->curveflags |= CURVE_KN_INTERSECTCORRECTION;
if(line_method == CURVE_POSTCORRECTED)
kcurve->curveflags |= CURVE_KN_POSTINTERSECTCORRECTION;
if(use_tangent_normal)
kcurve->curveflags |= CURVE_KN_TANGENTGNORMAL;
if(use_tangent_normal_correction)
kcurve->curveflags |= CURVE_KN_NORMALCORRECTION;
if(use_tangent_normal_geometry)
kcurve->curveflags |= CURVE_KN_TRUETANGENTGNORMAL;
if(use_joined)
kcurve->curveflags |= CURVE_KN_CURVEDATA;
if(use_backfacing)
kcurve->curveflags |= CURVE_KN_BACKFACING;
if(use_encasing)
kcurve->curveflags |= CURVE_KN_ENCLOSEFILTER;
kcurve->normalmix = normalmix;
kcurve->encasing_ratio = encasing_ratio;
kcurve->minimum_width = minimum_width;
kcurve->maximum_width = maximum_width;
kcurve->subdivisions = subdivisions;
}
if(progress.get_cancel()) return;
need_update = false;
}
void CurveSystemManager::device_free(Device *device, DeviceScene *dscene)
{
}
bool CurveSystemManager::modified(const CurveSystemManager& CurveSystemManager)
{
return !(line_method == CurveSystemManager.line_method &&
interpolation == CurveSystemManager.interpolation &&
primitive == CurveSystemManager.primitive &&
use_encasing == CurveSystemManager.use_encasing &&
use_tangent_normal == CurveSystemManager.use_tangent_normal &&
use_tangent_normal_correction == CurveSystemManager.use_tangent_normal_correction &&
use_tangent_normal_geometry == CurveSystemManager.use_tangent_normal_geometry &&
encasing_ratio == CurveSystemManager.encasing_ratio &&
minimum_width == CurveSystemManager.minimum_width &&
maximum_width == CurveSystemManager.maximum_width &&
use_backfacing == CurveSystemManager.use_backfacing &&
normalmix == CurveSystemManager.normalmix &&
use_smooth == CurveSystemManager.use_smooth &&
triangle_method == CurveSystemManager.triangle_method &&
resolution == CurveSystemManager.resolution &&
use_curves == CurveSystemManager.use_curves &&
use_joined == CurveSystemManager.use_joined &&
segments == CurveSystemManager.segments &&
use_parents == CurveSystemManager.use_parents &&
subdivisions == CurveSystemManager.subdivisions);
}
bool CurveSystemManager::modified_mesh(const CurveSystemManager& CurveSystemManager)
{
return !(primitive == CurveSystemManager.primitive &&
interpolation == CurveSystemManager.interpolation &&
use_parents == CurveSystemManager.use_parents &&
use_smooth == CurveSystemManager.use_smooth &&
triangle_method == CurveSystemManager.triangle_method &&
resolution == CurveSystemManager.resolution &&
use_curves == CurveSystemManager.use_curves &&
use_joined == CurveSystemManager.use_joined &&
segments == CurveSystemManager.segments);
}
void CurveSystemManager::tag_update(Scene *scene)
{
need_update = true;
}
void CurveSystemManager::tag_update_mesh()
{
need_mesh_update = true;
}
CCL_NAMESPACE_END