blender/intern/opensubdiv/internal/evaluator/eval_output_cpu.h

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OpenSubDiv: add support for an OpenGL evaluator This evaluator is used in order to evaluate subdivision at render time, allowing for faster renders of meshes with a subdivision surface modifier placed at the last position in the modifier list. When evaluating the subsurf modifier, we detect whether we can delegate evaluation to the draw code. If so, the subdivision is first evaluated on the GPU using our own custom evaluator (only the coarse data needs to be initially sent to the GPU), then, buffers for the final `MeshBufferCache` are filled on the GPU using a set of compute shaders. However, some buffers are still filled on the CPU side, if doing so on the GPU is impractical (e.g. the line adjacency buffer used for x-ray, whose logic is hardly GPU compatible). This is done at the mesh buffer extraction level so that the result can be readily used in the various OpenGL engines, without having to write custom geometry or tesselation shaders. We use our own subdivision evaluation shaders, instead of OpenSubDiv's vanilla one, in order to control the data layout, and interpolation. For example, we store vertex colors as compressed 16-bit integers, while OpenSubDiv's default evaluator only work for float types. In order to still access the modified geometry on the CPU side, for use in modifiers or transform operators, a dedicated wrapper type is added `MESH_WRAPPER_TYPE_SUBD`. Subdivision will be lazily evaluated via `BKE_object_get_evaluated_mesh` which will create such a wrapper if possible. If the final subdivision surface is not needed on the CPU side, `BKE_object_get_evaluated_mesh_no_subsurf` should be used. Enabling or disabling GPU subdivision can be done through the user preferences (under Viewport -> Subdivision). See patch description for benchmarks. Reviewed By: campbellbarton, jbakker, fclem, brecht, #eevee_viewport Differential Revision: https://developer.blender.org/D12406
2021-12-27 15:34:47 +00:00
// Copyright 2021 Blender Foundation. All rights reserved.
//
// 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.
//
// Author: Sergey Sharybin
#ifndef OPENSUBDIV_EVAL_OUTPUT_CPU_H_
#define OPENSUBDIV_EVAL_OUTPUT_CPU_H_
#include "internal/evaluator/eval_output.h"
#include <opensubdiv/osd/cpuEvaluator.h>
#include <opensubdiv/osd/cpuPatchTable.h>
#include <opensubdiv/osd/cpuVertexBuffer.h>
using OpenSubdiv::Far::StencilTable;
using OpenSubdiv::Osd::CpuEvaluator;
using OpenSubdiv::Osd::CpuVertexBuffer;
namespace blender {
namespace opensubdiv {
// NOTE: Define as a class instead of typedef to make it possible
OpenSubDiv: add support for an OpenGL evaluator This evaluator is used in order to evaluate subdivision at render time, allowing for faster renders of meshes with a subdivision surface modifier placed at the last position in the modifier list. When evaluating the subsurf modifier, we detect whether we can delegate evaluation to the draw code. If so, the subdivision is first evaluated on the GPU using our own custom evaluator (only the coarse data needs to be initially sent to the GPU), then, buffers for the final `MeshBufferCache` are filled on the GPU using a set of compute shaders. However, some buffers are still filled on the CPU side, if doing so on the GPU is impractical (e.g. the line adjacency buffer used for x-ray, whose logic is hardly GPU compatible). This is done at the mesh buffer extraction level so that the result can be readily used in the various OpenGL engines, without having to write custom geometry or tesselation shaders. We use our own subdivision evaluation shaders, instead of OpenSubDiv's vanilla one, in order to control the data layout, and interpolation. For example, we store vertex colors as compressed 16-bit integers, while OpenSubDiv's default evaluator only work for float types. In order to still access the modified geometry on the CPU side, for use in modifiers or transform operators, a dedicated wrapper type is added `MESH_WRAPPER_TYPE_SUBD`. Subdivision will be lazily evaluated via `BKE_object_get_evaluated_mesh` which will create such a wrapper if possible. If the final subdivision surface is not needed on the CPU side, `BKE_object_get_evaluated_mesh_no_subsurf` should be used. Enabling or disabling GPU subdivision can be done through the user preferences (under Viewport -> Subdivision). See patch description for benchmarks. Reviewed By: campbellbarton, jbakker, fclem, brecht, #eevee_viewport Differential Revision: https://developer.blender.org/D12406
2021-12-27 15:34:47 +00:00
// to have anonymous class in opensubdiv_evaluator_internal.h
class CpuEvalOutput : public VolatileEvalOutput<CpuVertexBuffer,
CpuVertexBuffer,
StencilTable,
CpuPatchTable,
CpuEvaluator> {
public:
CpuEvalOutput(const StencilTable *vertex_stencils,
const StencilTable *varying_stencils,
const vector<const StencilTable *> &all_face_varying_stencils,
const int face_varying_width,
const PatchTable *patch_table,
EvaluatorCache *evaluator_cache = NULL)
: VolatileEvalOutput<CpuVertexBuffer,
CpuVertexBuffer,
StencilTable,
CpuPatchTable,
CpuEvaluator>(vertex_stencils,
varying_stencils,
all_face_varying_stencils,
face_varying_width,
patch_table,
evaluator_cache)
{
}
};
} // namespace opensubdiv
} // namespace blender
#endif // OPENSUBDIV_EVAL_OUTPUT_CPU_H_