9.3.4 变形体动画之对折硬纸

动画关键帧创建与实时MorphGeometry应用

原创已于 2023-06-25 12:33:26 修改 · 316 阅读

1 ·

CC 4.0 BY-SA版权

文章标签：

#c++ #c# #动画

于 2021-03-28 11:12:37 首次发布

《OpenSceneGrap三维渲染引擎设计与实践》源码专栏收录该内容

10 篇文章

订阅专栏

本文展示了如何使用osgAnimation库创建动态关键帧，并实现两个几何体之间的实时Morph变形。通过创建源和目标几何体，定义关键帧并创建动画，最后将动画应用到osg::Geode中，实现了可视化效果。

#include <osgViewer/Viewer>
#include <osg/Node>
#include <osg/Geometry>
#include <osg/Geode>
#include <osg/Group>
#include <osg/AutoTransform>
#include <osg/ProxyNode>
#include <osgDB/ReadFile>
#include <osgDB/WriteFile>
#include <osgText/Text>
#include <osgUtil/Optimizer>
#include<osg/Camera>
#include<osgViewer/Viewer>
#include <osgManipulator/Dragger>
#include <osgManipulator/Selection>
#include <osgManipulator/Constraint>
#include <osgManipulator/TranslateAxisDragger>
#include <osgManipulator/CommandManager>
#include<osgFX/Scribe>
#include<osg/MatrixTransform>
#include<osgAnimation/Animation>
#include<osgAnimation/Bone>
#include<osgAnimation/Skeleton>
#include<osgAnimation/UpdateMatrixTransform>
#include<osgAnimation/BasicAnimationManager>
#include<osgAnimation/MorphGeometry>
#include<osgUtil/SmoothingVisitor>
#include <iostream>
#include <thread>
#include <future>
#include <string>
#include<map>
#include<vector>
#include<list>
using std::vector;
using std::string;
using std::list;
using namespace std;

osg::Geometry* createSourceGeometry()
{
	osg::ref_ptr<osg::Vec3Array> vertices = new osg::Vec3Array;
	vertices->push_back(osg::Vec3(0.0, 5.0, -2.5));
	vertices->push_back(osg::Vec3(0.0, 0.0, -2.5));
	vertices->push_back(osg::Vec3(2.5, 5.0, 0.0));
	vertices->push_back(osg::Vec3(2.5, 0.0, 0.0));
	vertices->push_back(osg::Vec3(5.0, 5.0, -2.5));
	vertices->push_back(osg::Vec3(5.0, 0.0, -2.5));
    
	osg::ref_ptr<osg::Geometry> geom = new osg::Geometry;
	geom->setVertexArray(vertices.get());
	geom->addPrimitiveSet(new osg::DrawArrays(GL_QUAD_STRIP, 0, 6));
	osgUtil::SmoothingVisitor smv;
	smv.smooth(*geom);

	return geom.release();
}

osg::Geometry* createTargetGeometry()
{
	osg::ref_ptr<osg::Vec3Array> vertices = new osg::Vec3Array;
	vertices->push_back(osg::Vec3(0.0, 5.0, 1.0));
	vertices->push_back(osg::Vec3(0.0, 0.0, 1.0));
	vertices->push_back(osg::Vec3(2.5, 5.0, -1.0));
	vertices->push_back(osg::Vec3(2.5, 0.0, -1.0));
	vertices->push_back(osg::Vec3(5.0, 5.0, 1.0));
	vertices->push_back(osg::Vec3(5.0, 0.0, 1.0));

	osg::ref_ptr<osg::Geometry> geom = new osg::Geometry;
	geom->setVertexArray(vertices.get());
	geom->addPrimitiveSet(new osg::DrawArrays(GL_QUAD_STRIP, 0, 6));
	osgUtil::SmoothingVisitor smv;
	smv.smooth(*geom);

	return geom.release();
}

void createMorphKeyframes(osgAnimation::FloatKeyframeContainer* ks)
{
	ks->push_back(osgAnimation::FloatKeyframe(0.0, 0.0));
	ks->push_back(osgAnimation::FloatKeyframe(2.0, 1.0));
}
int main()
{
	osg::ref_ptr<osgAnimation::FloatLinearChannel> channel = new osgAnimation::FloatLinearChannel;
	channel->setName("0");
	channel->setTargetName("MorphCallback");

	createMorphKeyframes(channel->getOrCreateSampler()->getOrCreateKeyframeContainer());
	osg::ref_ptr<osgAnimation::Animation> anim = new osgAnimation::Animation;
    anim->setPlaymode(osgAnimation::Animation::PPONG)
	anim->addChannel(channel.get());

	osg::ref_ptr<osgAnimation::BasicAnimationManager> manager = new osgAnimation::BasicAnimationManager;
	manager->registerAnimation(anim.get());

	osg::ref_ptr<osgAnimation::MorphGeometry> morph = new osgAnimation::MorphGeometry(*createSourceGeometry());
	morph->addMorphTarget(createTargetGeometry());

	osg::ref_ptr<osg::Geode> geode = new osg::Geode;
	geode->addDrawable(morph.get());
	geode->setUpdateCallback(new osgAnimation::UpdateMorph("MorphCallback"));
	osg::ref_ptr<osg::Group> root = new osg::Group;
	root->addChild(geode.get());
	root->setUpdateCallback(manager.get());

	manager->playAnimation(anim.get());

	osgViewer::Viewer viewer;
	viewer.setSceneData(root.get());
	return viewer.run();
}