SkylineGlobe 7.0.1 & 7.0.2版本Web开发 如何实现对三维模型和地形的剖切展示

现在很多三维项目中，不仅仅要用到三维地形，正射影像和矢量数据，还会融合到各种三维模型，包括传统的3DMax手工建模，BIM，倾斜摄影自动建模，激光点云模型，三维地质体模型等等。

三维平台首先要做的是把这些多源数据承载进来，并且要能够流畅，稳定地运行使用。

接下来就是各种展示，应用，分析。

三维剖切，就是一种较好的展示复杂结构模型的方法，比如应用于BIM，室内精细建模，三维地质体模型等。

SkylineGlobe提供的核心示例代码如下：

//-------------------
        function showCrossSection(gBoxObj) {
            try {
                var SGWorld = CreateSGObj();
                    var vertices = [];
                    var sectionSize = gBoxObj.Width * 5;
                    gLastPos = gBoxObj.Position.Copy();
                    var pos = gBoxObj.Position;
                    var planeTolarance = 100 / 100;
                    if (gBoxObj.Position.Pitch == 90) {
                        var yaw = gBoxObj.Position.Yaw - 180;
                        pos = pos.Move(planeTolarance, yaw - 180, 0);  // make sure the cut area doesn't include the box
                        pos = pos.Move(gBoxObj.Width / 2, 0, -90);
                        pos = pos.Move(gBoxObj.Width / 2, yaw + 90, 0);
                        vertices[0] = pos;
                        pos = pos.Move(sectionSize, yaw - 180, 0);
                        vertices[1] = pos;
                        pos = pos.Move(gBoxObj.Width, yaw - 90, 0);
                        vertices[2] = pos;
                        pos = pos.Move(sectionSize, yaw, 0);
                        vertices[3] = pos;
                        vertices[4] = vertices[0].Move(gBoxObj.Width, 0, 90);
                        vertices[5] = vertices[1].Move(gBoxObj.Width, 0, 90);
                        vertices[6] = vertices[2].Move(gBoxObj.Width, 0, 90);
                        vertices[7] = vertices[3].Move(gBoxObj.Width, 0, 90);
                    }
                    else {
                        pos = pos.Move(planeTolarance, 0, 90);  // make sure the cut area doesn't include the box
                        pos = pos.Move(gBoxObj.Width / 2, gBoxObj.Position.Yaw, 0);
                        pos = pos.Move(gBoxObj.Width / 2, gBoxObj.Position.Yaw + 90, 0);
                        vertices[0] = pos;
                        pos = pos.Move(gBoxObj.Width, gBoxObj.Position.Yaw - 180, 0);
                        vertices[1] = pos;
                        pos = pos.Move(gBoxObj.Width, gBoxObj.Position.Yaw - 90, 0);
                        vertices[2] = pos;
                        pos = pos.Move(gBoxObj.Width, gBoxObj.Position.Yaw, 0);
                        vertices[3] = pos;
                        vertices[4] = vertices[0].Move(sectionSize, 0, 90);
                        vertices[5] = vertices[1].Move(sectionSize, 0, 90);
                        vertices[6] = vertices[2].Move(sectionSize, 0, 90);
                        vertices[7] = vertices[3].Move(sectionSize, 0, 90);
                    }

                    gGeometry = SGWorld.Creator.GeometryCreator.CreateLineStringGeometry(vertices);
                    SGWorld.Analysis.ShowCrossSectionBox(gGeometry, false, 0xffffffff);
            }
            catch (err) {}
        }

        function HideCrossSectionBox()
        {
            if (syBoxobj != null) {
                var sg = CreateSGObj();
                sg.Analysis.HideCrossSectionBox();
                sg.Creator.DeleteObject(syBoxobj.ID);
                syBoxobj = null;
            }
        }

完整的功能实现代码在C:\Program Files\Skyline\TerraExplorer Pro\Tools\CrossSection这个目录里。