osg设置模型纹理

osg设置模型纹理

• • 概述：
  • 示例代码：

概述：

1.开发随笔记录分享两种纹理设置方式：
a.自定义顶点方式进行设置纹理坐标；
b.自动生成纹理坐标

示例代码：

自动生成纹理坐标

	//读取文件路径
	std::string path = CSingletonShared::GetInstance().GetApplicationPath();
	osg::ref_ptr<osg::Image> image = osgDB::readImageFile(CSingletonShared::GetInstance().GetApplicationPath() + "\\TeeImage.jpg");
	if (image.get())
	{
		osg::ref_ptr<osg::Texture2D> texture = new osg::Texture2D();
		texture->setImage(image.get());
		//设置自动生成纹理坐标
		osg::ref_ptr<osg::TexGen> texgen = new osg::TexGen();
		texgen->setMode(osg::TexGen::SPHERE_MAP);
		//设置纹理环境，模式为BLEND
		osg::ref_ptr<osg::TexEnv> texenv = new osg::TexEnv;
		texenv->setMode(osg::TexEnv::Mode::ADD);
		//texenv->setColor(osg::Vec4(0.6, 0.6, 0.6, 0.0));
		//启动单元一自动生成纹理坐标，并使用纹理
		osg::ref_ptr<osg::StateSet> state = new osg::StateSet;
		state->setTextureAttributeAndModes(1, texture.get(), osg::StateAttribute::ON);
		state->setTextureAttributeAndModes(1, texgen.get(), osg::StateAttribute::ON);
		state->setTextureAttribute(1, texenv.get());
		node->setStateSet(state.get());
	}
	pSceneRoot->addChild(node);

自定义顶点方式设置纹理坐标

bool RackVolume::Model_Create(osg::Node * _node)
{
	if (nullptr == _node)
	{
		return false;
	}
	osg::ref_ptr<osg::Group> pGroop = new osg::Group;
	osg::ref_ptr<osg::Geometry> pGeometry = new osg::Geometry;
	osg::ref_ptr<osg::Vec3Array> pVec3 = new osg::Vec3Array;
	pVec3->push_back(osg::Vec3(0.0, 0.0, 1.0));
	pVec3->push_back(osg::Vec3(1.0, 0.0, 1.0));
	pVec3->push_back(osg::Vec3(1.0, 1.0, 1.0));
	pVec3->push_back(osg::Vec3(0.0, 1.0, 1.0));
	// 添加四个顶点
	pGeometry->setVertexArray(pVec3.get());
	std::string path = CSingletonShared::GetInstance().GetApplicationPath();
	osg::ref_ptr<osg::Image> image = osgDB::readImageFile(CSingletonShared::GetInstance().GetApplicationPath() + "\\TeeImage.jpg");
	if (image.get())
	{
		osg::ref_ptr<osg::Texture2D> texture2D = new osg::Texture2D;
		texture2D->setImage(image.get());
		// 绑定纹理后，释放内部的ref_ptr<Image>，删除image图像
		texture2D->setUnRefImageDataAfterApply(true);
		// 建立纹理顶点
		osg::ref_ptr<osg::Vec2Array> pVec2Array = new osg::Vec2Array;
		//纹理单元号
		pVec2Array->push_back(osg::Vec2(0.0, 0.0));
		pVec2Array->push_back(osg::Vec2(1.0, 0.0));
		pVec2Array->push_back(osg::Vec2(1.0, 1.0));
		pVec2Array->push_back(osg::Vec2(0.0,1.0));
		
		// 失败
		// osg::ref_ptr<osg::StateSet> pStateSet = new osg::StateSet;
		// Texture类关联到渲染状态StateSet
		osg::ref_ptr<osg::StateSet> pStateSet = pGeometry->getOrCreateStateSet();
		// 将纹理关联给StateSet纹理单元0、osg::StateAttribute::OFF关闭纹理
		pStateSet->setTextureAttributeAndModes(0, texture2D.get(), osg::StateAttribute::ON);
		pGeometry->setTexCoordArray(0, pVec2Array.get());
		// 建立法线一个数组    法线: normal
		osg::ref_ptr<osg::Vec3Array> pVec3ArrayNormal = new osg::Vec3Array;
		pGeometry->setNormalArray(pVec3ArrayNormal.get());
		pGeometry->setNormalBinding(osg::Geometry::BIND_OVERALL);
		//垂直于Z轴负方向
		pVec3ArrayNormal->push_back(osg::Vec3(0.0, 0.0, -1.0));
		pGeometry->setStateSet(pStateSet);
		// 保存的数据绘制四个顶点的多边形
		pGeometry->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, 4));
		// 向Geode类添加几何体(Drawable)
		osg::ref_ptr<osg::Geode> pGeode = new osg::Geode;
		pGeode->addDrawable(pGeometry.get());
		pGroop->addChild(pGeode);
	}
	//创建一个矩阵
	osg::ref_ptr<osg::MatrixTransform> ms = new osg::MatrixTransform;
	ms->setMatrix(osg::Matrix::scale(_info.fXRate, _info.fYRate, _info.fZRate)
		*osg::Matrix::rotate(osg::DegreesToRadians(-_info.fRotationAngle), osg::Z_AXIS)
		*osg::Matrix::translate(_info.fXcoordinate, _info.fYcoordinate, _info.fZcoordinate)
	);
	ms->addChild(nodeDragger);
	ms->setName(_info.str_ID);
	pGroop->addChild(ms/*.release()*/);
	pSceneRoot->addChild(pGroop->asNode());
	return true;
}

over:

欢迎大家关注作者在文末评论、点赞、转发以及批评指正！
如果大家有更好的方法或有问题可以在文末评论一起讨论！
共同学习！
共同进步！

文末一句话：

既要知其然也要知其所以然；