This repository has been archived on 2023-10-09. You can view files and clone it. You cannot open issues or pull requests or push a commit.
Files
blender-archive/source/blender/freestyle/intern/view_map/AverageAreaGridDensityProvider.cpp
Tamito Kajiyama b614b81a77 Fix for [#35245] Freestyle getting stuck on view map creation + memory leaks.
There were two issues:

- Line visibility computations are very slow in the case of the provided .blend file, which gave
an impression that the rendering process got stuck.  The slowness can be explained by the present
data structures used for the line visibility computations, together with the specific mesh distribution
of the test scene.  At the moment Freestyle uses a regular grid in the 2D image coordinate system
to divide tris/quads into small groups in order to accelerate the line visibility computations.
On the other hand, the test scene is populated a big plane (made of one quad) and a moderately
detailed mesh object (22K tris).  The scale of the latter mesh is animated from nearly zero to
about 0.2 to make the object show up over time.  When the scale is nearly equal to zero, all the
tris concentrate in one grid cell, so essentially there is no performance gain from the grid data
structure optimized for speed.  It looks like a better grid data structure (possibly based on
adaptive grid refinement) is necessary to genuinely address the identified performance issue.  For now
the progress bar of Blender is employed to better inform users of the amount of work done in the line
visibility computations.

- A crash was caused by an excessive memory allocation request.  The X and Y dimensions of the grid
data structure are determined based on the average area of mesh faces in the given scene.  When the big
plane in the test scene is excluded from the rendering, the average area is almost zero (on the order
of 1e-5).  As a result of this extremely small average area, the X and Y dimensions were set to a very
large number, causing a fatal memory allocation error.  The present revision has introduced a hard
upper limit to the dimensions of the grid data structure to avoid this kind of numerical instability.
2013-05-19 00:56:40 +00:00

143 lines
5.1 KiB
C++

/*
* ***** BEGIN GPL LICENSE BLOCK *****
*
* 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.
*
* ***** END GPL LICENSE BLOCK *****
*/
/** \file blender/freestyle/intern/view_map/AverageAreaGridDensityProvider.cpp
* \ingroup freestyle
* \brief Class to define a cell grid surrounding the projected image of a scene
* \author Alexander Beels
* \date 2011-2-9
*/
#include "AverageAreaGridDensityProvider.h"
#include "BKE_global.h"
namespace Freestyle {
AverageAreaGridDensityProvider::AverageAreaGridDensityProvider(OccluderSource& source, const real proscenium[4],
real sizeFactor)
: GridDensityProvider(source)
{
initialize (proscenium, sizeFactor);
}
AverageAreaGridDensityProvider::AverageAreaGridDensityProvider(OccluderSource& source, const BBox<Vec3r>& bbox,
const GridHelpers::Transform& transform, real sizeFactor)
: GridDensityProvider(source)
{
real proscenium[4];
calculateQuickProscenium(transform, bbox, proscenium);
initialize(proscenium, sizeFactor);
}
AverageAreaGridDensityProvider::AverageAreaGridDensityProvider(OccluderSource& source, real sizeFactor)
: GridDensityProvider(source)
{
real proscenium[4];
calculateOptimalProscenium(source, proscenium);
initialize(proscenium, sizeFactor);
}
AverageAreaGridDensityProvider::~AverageAreaGridDensityProvider() {}
void AverageAreaGridDensityProvider::initialize(const real proscenium[4], real sizeFactor)
{
float prosceniumWidth = (proscenium[1] - proscenium[0]);
float prosceniumHeight = (proscenium[3] - proscenium[2]);
real cellArea = 0.0;
unsigned numFaces = 0;
for (source.begin(); source.isValid(); source.next()) {
Polygon3r& poly(source.getGridSpacePolygon());
Vec3r min, max;
poly.getBBox(min, max);
cellArea += (max[0] - min[0]) * (max[1] - min[1]);
++numFaces;
}
if (G.debug & G_DEBUG_FREESTYLE) {
cout << "Total area: " << cellArea << ". Number of faces: " << numFaces << "." << endl;
}
cellArea /= numFaces;
cellArea *= sizeFactor;
if (G.debug & G_DEBUG_FREESTYLE) {
cout << "Building grid with average area " << cellArea << endl;
}
_cellSize = sqrt(cellArea);
unsigned maxCells = 931; // * 1.1 = 1024
if (std::max(prosceniumWidth, prosceniumHeight) / _cellSize > maxCells) {
if (G.debug & G_DEBUG_FREESTYLE) {
cout << "Scene-dependent cell size (" << _cellSize << " square) is too small." << endl;
}
_cellSize = std::max(prosceniumWidth, prosceniumHeight) / maxCells;
}
// Now we know how many cells make each side of our grid
_cellsX = ceil(prosceniumWidth / _cellSize);
_cellsY = ceil(prosceniumHeight / _cellSize);
if (G.debug & G_DEBUG_FREESTYLE) {
cout << _cellsX << "x" << _cellsY << " cells of size " << _cellSize << " square." << endl;
}
// Make sure the grid exceeds the proscenium by a small amount
float safetyZone = 0.1f;
if (_cellsX * _cellSize < prosceniumWidth * (1.0 + safetyZone)) {
_cellsX = prosceniumWidth * (1.0 + safetyZone) / _cellSize;
}
if (_cellsY * _cellSize < prosceniumHeight * (1.0 + safetyZone)) {
_cellsY = prosceniumHeight * (1.0 + safetyZone) / _cellSize;
}
if (G.debug & G_DEBUG_FREESTYLE) {
cout << _cellsX << "x" << _cellsY << " cells of size " << _cellSize << " square." << endl;
}
// Find grid origin
_cellOrigin[0] = ((proscenium[0] + proscenium[1]) / 2.0) - (_cellsX / 2.0) * _cellSize;
_cellOrigin[1] = ((proscenium[2] + proscenium[3]) / 2.0) - (_cellsY / 2.0) * _cellSize;
}
AverageAreaGridDensityProviderFactory::AverageAreaGridDensityProviderFactory(real sizeFactor)
: sizeFactor(sizeFactor)
{
}
AverageAreaGridDensityProviderFactory::~AverageAreaGridDensityProviderFactory() {}
auto_ptr<GridDensityProvider>
AverageAreaGridDensityProviderFactory::newGridDensityProvider(OccluderSource& source, const real proscenium[4])
{
return auto_ptr<GridDensityProvider>(new AverageAreaGridDensityProvider(source, proscenium, sizeFactor));
}
auto_ptr<GridDensityProvider>
AverageAreaGridDensityProviderFactory::newGridDensityProvider(OccluderSource& source, const BBox<Vec3r>& bbox,
const GridHelpers::Transform& transform)
{
return auto_ptr<GridDensityProvider>(new AverageAreaGridDensityProvider(source, bbox, transform, sizeFactor));
}
auto_ptr<GridDensityProvider> AverageAreaGridDensityProviderFactory::newGridDensityProvider(OccluderSource& source)
{
return auto_ptr<GridDensityProvider>(new AverageAreaGridDensityProvider(source, sizeFactor));
}
} /* namespace Freestyle */