在Revit中有一个相机功能可以以相机视角产生一个视图。一开始我在Revit2016的API文档中找关键词Camera，但是没什么收获。
其实这个相机功能的真正核心是创建透视视图：View3D.CreatePerspective(Document, ElementId)
简单的代码示例如下：
var uiDocument = commandData.Application.ActiveUIDocument;
var doc = uiDocument.Document;
IEnumerable<ViewFamilyType> viewFamilyTypes = from elem in new FilteredElementCollector(doc).OfClass(typeof(ViewFamilyType))
let type = elem as ViewFamilyType
where type.ViewFamily == ViewFamily.ThreeDimensional
select type;
using (Transaction tran = new Transaction(doc, "[ToolSet] Camera"))
{
tran.start();
View3D view3D = View3D.CreatePerspective(doc, viewFamilyTypes.First().Id);
if (null != view3D)
{
var eye = new XYZ(0,0,100); //相机坐标
var up = new XYZ(0,0,1); //上方向
var forward = new XYZ(3,4,5); //相机到目标点的向量
view3D.SetOrientation(new ViewOrientation3D(eye, up, forward));
view3D.DisplayStyle = DisplayStyle.ShadingWithEdges;
}
tran.Commit(); UIDocument RevitUiDoc = new UIDocument(doc);
RevitUiDoc.ActiveView = view3D;
}
关于上方向：
Autodesk的View3D博客：