blender/intern/cycles/render/image_vdb.cpp
Kévin Dietrich 9280fb19e4 Fixes T77882: artifacts rendering OpenVDB volumes with multiple grids in Cycles
The previous algorithm was not using all of the requested grids to build a mesh
around the volume due to limitations regarding the use of a dense buffer to
gather information about the volume's topology. This resulted in artefacts during
rendering.

The mesh generation is now done by merging all of the input grids and using the
resulting grid's topology to create the mesh. The generation of the mesh
is still done in index space as before, and the vertices are converted to object
space by using the merged topology grid indexToWorld transform.

To be able to merge the grids together we have to make sure that their transformation
matrices and their index spaces match, thus, if they do not match we simply resample
the grids. This behaviour should tackle one other limitation of the current algorithm,
which is that only one transformation matrix was used to generate the final mesh.

If we do not have an OpenVDB grid for the requested volume data, we generate
a temporary OpenVDB grid for it.

Differential Revision: https://developer.blender.org/D8401
2020-08-12 11:52:12 +02:00

201 lines
5.7 KiB
C++

/*
* Copyright 2011-2020 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "render/image_vdb.h"
#ifdef WITH_OPENVDB
# include <openvdb/openvdb.h>
# include <openvdb/tools/Dense.h>
#endif
CCL_NAMESPACE_BEGIN
VDBImageLoader::VDBImageLoader(const string &grid_name) : grid_name(grid_name)
{
}
VDBImageLoader::~VDBImageLoader()
{
}
bool VDBImageLoader::load_metadata(ImageMetaData &metadata)
{
#ifdef WITH_OPENVDB
if (!grid) {
return false;
}
bbox = grid->evalActiveVoxelBoundingBox();
if (bbox.empty()) {
return false;
}
/* Set dimensions. */
openvdb::Coord dim = bbox.dim();
openvdb::Coord min = bbox.min();
metadata.width = dim.x();
metadata.height = dim.y();
metadata.depth = dim.z();
/* Set data type. */
if (grid->isType<openvdb::FloatGrid>()) {
metadata.channels = 1;
}
else if (grid->isType<openvdb::Vec3fGrid>()) {
metadata.channels = 3;
}
else if (grid->isType<openvdb::BoolGrid>()) {
metadata.channels = 1;
}
else if (grid->isType<openvdb::DoubleGrid>()) {
metadata.channels = 1;
}
else if (grid->isType<openvdb::Int32Grid>()) {
metadata.channels = 1;
}
else if (grid->isType<openvdb::Int64Grid>()) {
metadata.channels = 1;
}
else if (grid->isType<openvdb::Vec3IGrid>()) {
metadata.channels = 3;
}
else if (grid->isType<openvdb::Vec3dGrid>()) {
metadata.channels = 3;
}
else if (grid->isType<openvdb::MaskGrid>()) {
metadata.channels = 1;
}
else {
return false;
}
if (metadata.channels == 1) {
metadata.type = IMAGE_DATA_TYPE_FLOAT;
}
else {
metadata.type = IMAGE_DATA_TYPE_FLOAT4;
}
/* Set transform from object space to voxel index. */
openvdb::math::Mat4f grid_matrix = grid->transform().baseMap()->getAffineMap()->getMat4();
Transform index_to_object;
for (int col = 0; col < 4; col++) {
for (int row = 0; row < 3; row++) {
index_to_object[row][col] = (float)grid_matrix[col][row];
}
}
Transform texture_to_index = transform_translate(min.x(), min.y(), min.z()) *
transform_scale(dim.x(), dim.y(), dim.z());
metadata.transform_3d = transform_inverse(index_to_object * texture_to_index);
metadata.use_transform_3d = true;
return true;
#else
(void)metadata;
return false;
#endif
}
bool VDBImageLoader::load_pixels(const ImageMetaData &, void *pixels, const size_t, const bool)
{
#ifdef WITH_OPENVDB
if (grid->isType<openvdb::FloatGrid>()) {
openvdb::tools::Dense<float, openvdb::tools::LayoutXYZ> dense(bbox, (float *)pixels);
openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::FloatGrid>(grid), dense);
}
else if (grid->isType<openvdb::Vec3fGrid>()) {
openvdb::tools::Dense<openvdb::Vec3f, openvdb::tools::LayoutXYZ> dense(
bbox, (openvdb::Vec3f *)pixels);
openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::Vec3fGrid>(grid), dense);
}
else if (grid->isType<openvdb::BoolGrid>()) {
openvdb::tools::Dense<float, openvdb::tools::LayoutXYZ> dense(bbox, (float *)pixels);
openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::BoolGrid>(grid), dense);
}
else if (grid->isType<openvdb::DoubleGrid>()) {
openvdb::tools::Dense<float, openvdb::tools::LayoutXYZ> dense(bbox, (float *)pixels);
openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::DoubleGrid>(grid), dense);
}
else if (grid->isType<openvdb::Int32Grid>()) {
openvdb::tools::Dense<float, openvdb::tools::LayoutXYZ> dense(bbox, (float *)pixels);
openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::Int32Grid>(grid), dense);
}
else if (grid->isType<openvdb::Int64Grid>()) {
openvdb::tools::Dense<float, openvdb::tools::LayoutXYZ> dense(bbox, (float *)pixels);
openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::Int64Grid>(grid), dense);
}
else if (grid->isType<openvdb::Vec3IGrid>()) {
openvdb::tools::Dense<openvdb::Vec3f, openvdb::tools::LayoutXYZ> dense(
bbox, (openvdb::Vec3f *)pixels);
openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::Vec3IGrid>(grid), dense);
}
else if (grid->isType<openvdb::Vec3dGrid>()) {
openvdb::tools::Dense<openvdb::Vec3f, openvdb::tools::LayoutXYZ> dense(
bbox, (openvdb::Vec3f *)pixels);
openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::Vec3dGrid>(grid), dense);
}
else if (grid->isType<openvdb::MaskGrid>()) {
openvdb::tools::Dense<float, openvdb::tools::LayoutXYZ> dense(bbox, (float *)pixels);
openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::MaskGrid>(grid), dense);
}
return true;
#else
(void)pixels;
return false;
#endif
}
string VDBImageLoader::name() const
{
return grid_name;
}
bool VDBImageLoader::equals(const ImageLoader &other) const
{
#ifdef WITH_OPENVDB
const VDBImageLoader &other_loader = (const VDBImageLoader &)other;
return grid == other_loader.grid;
#else
(void)other;
return true;
#endif
}
void VDBImageLoader::cleanup()
{
#ifdef WITH_OPENVDB
/* Free OpenVDB grid memory as soon as we can. */
grid.reset();
#endif
}
bool VDBImageLoader::is_vdb_loader() const
{
return true;
}
#ifdef WITH_OPENVDB
openvdb::GridBase::ConstPtr VDBImageLoader::get_grid()
{
return grid;
}
#endif
CCL_NAMESPACE_END