Cycles: Improved robustness of hair motion blur.motion_curve_fix

In some instances, the number of control vertices of a hair could change mid-frame.
Cycles would then be unable to calculate proper motion blur for those hairs. This adds
interpolated CVs to fill in for the missing data. While this will not necessarily result in
a fully accurate reconstruction of the guide hair, it preserves motion blur instead of disabling it.

Reviewers: #cycles, sergey

Reviewed By: #cycles, sergey

Subscribers: sergey, brecht, #cycles

Tags: #cycles

Differential Revision: https://developer.blender.org/D3695

1 files changed, 49 insertions, 0 deletions

diff --git a/intern/cycles/render/coverage.h b/intern/cycles/render/coverage.h
new file mode 100644
index 00000000000..9ee0bce7517
--- /dev/null
+++ b/intern/cycles/render/coverage.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2018 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/buffers.h"
+#include "kernel/kernel_compat_cpu.h"
+#include "kernel/split/kernel_split_data.h"
+#include "kernel/kernel_globals.h"
+#include "util/util_map.h"
+#include "util/util_vector.h"
+
+#ifndef __COVERAGE_H__
+#define __COVERAGE_H__
+
+CCL_NAMESPACE_BEGIN
+
+class Coverage {
+public:
+	Coverage(KernelGlobals *kg_, RenderTile &tile_) : kg(kg_), tile(tile_) { }
+	void init_path_trace();
+	void init_pixel(int x, int y);
+	void finalize();
+private:
+	vector<CoverageMap>coverage_object;
+	vector<CoverageMap>coverage_material;
+	vector<CoverageMap>coverage_asset;
+	KernelGlobals *kg;
+	RenderTile &tile;
+	void finalize_buffer(vector<CoverageMap>&coverage, const int pass_offset);
+	void flatten_buffer(vector<CoverageMap>&coverage, const int pass_offset);
+	void sort_buffer(const int pass_offset);
+};
+
+
+CCL_NAMESPACE_END
+
+#endif  /* __COVERAGE_H__ */