This allows adding a "fake" sun beam effect, simulating crepuscular rays from light being scattered in a medium like the atmosphere or deep water. Such effects can be created also by renderers using volumetric lighting, but the compositor feature is a lot cheaper and is independent from 3D rendering. This makes it ideally suited for motion graphics. The implementation uses am optimized accumulation method for gathering color values along a line segment. The inner buffer loop uses fixed offset increments to avoid unnecessary multiplications and avoids variables by using compile-time specialization (see inline comments for further details).
		
			
				
	
	
		
			49 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			49 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
/*
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 * Copyright 2014, Blender Foundation.
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 *
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 * This program is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU General Public License
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 * as published by the Free Software Foundation; either version 2
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 * of the License, or (at your option) any later version.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with this program; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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 *
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 * Contributor:
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 *		Lukas Toenne
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 */
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#ifndef _COM_SunBeamsOperation_h
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#define _COM_SunBeamsOperation_h
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#include "COM_NodeOperation.h"
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class SunBeamsOperation : public NodeOperation {
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public:
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	SunBeamsOperation();
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	void executePixel(float output[4], int x, int y, void *data);
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	void initExecution();
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	void *initializeTileData(rcti *rect);
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	bool determineDependingAreaOfInterest(rcti *input, ReadBufferOperation *readOperation, rcti *output);
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	void setData(const NodeSunBeams &data) { m_data = data; }
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private:
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	NodeSunBeams m_data;
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	float m_source_px[2];
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	float m_ray_length_px;
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};
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#endif
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