3D analysis |
Click the 
icon in the toolbar to bring up the 3D Analysis dialog box. The iEarth WebApp provides spatial analysis, cropping, and terrain manipulation functions to assist you in previewing effects or making decisions. This section describes in detail how to use these analysis functions.
Selecting the 
icon, the iEarth WebApp supports through-view analysis, viewable area analysis, shadow analysis, profile analysis, skyline analysis, and elevation maps.
Set the position of the observation point and the observed point in the scene to determine whether the two points are in view or not.
Operation: Select "Through View", set the result display parameters (visible area color, invisible color, obstacle highlight color), click "Analyze", click to draw the observation point position in the scene, move the mouse to click to draw the position of the observed point, that is, it will produce A line with color from the observation point to the observed point, the default green section of the line indicates that the line is visible, the red section of the line indicates that the line is invisible; you can move the mouse to draw more than one observed point for analysis. After analyzing, you can also click "Highlight Obstacles", the model that obstructs the line of sight during the analysis process will be highlighted according to the set obstacle highlighting color.
Analyzes the visibility within a specified field of view based on a specified observation point and the horizontal and vertical viewpoints of the observer.
Operation: Select "visual field", set the additional height (meters) of the observation point to be analyzed, click "Analyze", click to draw the observation point in the scene (it will be displayed based on the additional height set), and then move the mouse to display the visibility situation within the field of view of the real-time dynamic display from the point of view to the current mouse position. Move the mouse, it will dynamically display the visibility from the viewpoint to the current mouse position within the field of view, the green area represents visible, the red area represents invisible; click the right mouse button to determine the termination range of the analysis, at this time, you can adjust the scope of the analysis area and the color filling in the panel according to the need to modify the angle of the direction, the angle of the pitch, the horizontal angle of view, the vertical angle of view, the visible area and the invisible area of the color.
According to the latitude and longitude range of the region, calculate the shadows of the region exposed to the sun during the specified time period, and also simulate the change of sunlight effect with time.
Operation: Select "Shadow", select the date and time period (start time and end time), the bottom elevation and stretch height of the shadow, click the "Shadow" button, that is, it will be loaded for the model in the scene to the end of the time point of the shadow effect, and at the same time, at this time, in the scene, the mouse becomes the drawing state, you can At the same time, at this time, in the scene, the mouse becomes the drawing state, you can draw the surface area in the scene, that is, it will analyze the lighting rate in the specified time range within the drawing range; click "Sunshine Effect", it will dynamically display the shadow changes of the model from the start time to the end time range of the model being irradiated by the sun.
Draw a profile line in any direction on the terrain or model in the scene, which will automatically generate the changes of the terrain surface or model height along the profile line (or cross-section).
Operation: Select "Profile", click the "Analyze" button, draw a straight line or a folded line in the scene, click the right mouse button to end the drawing, which will pop up the results of the analysis of the profile line display panel.
According to the selected viewpoint, draw the separation line between the top edge of the building and the sky (skyline) in the current scene window. This can be used to analyze the height limit of buildings in urban planning and design.
Operation: Select "Skyline", click "Analyze" button to generate the skyline of the current scene window range, you can also adjust the display style of the result in the panel, such as: skyline color, display mode, etc.; click "2D Display". Click "2D Display" to output 2D skyline; click "Highlight Obstacles" to highlight the obstacles within the skyline.
Reflects the appearance of the building and the effect of façade decoration.
Operation: Select "Elevation", set the maximum height (meters), the farthest distance (meters), click "Draw", the mouse becomes the drawing state in the scene, you can draw in the scene, click the right mouse button to end the drawing. Click on "Map" to map the area you have drawn. Click "Clear" to clear the drawing result.
By selecting the 
icon, the iEarth WebApp supports four types of cropping: Box Crop, Flat Crop, Cross Crop and Polygon Crop.
Box Crop is to set the Box area for the model, and display the scene inside or outside the Box area in three dimensions.
Operation: Select "Box Crop", set the length/width/height (in meters) and rotation angle of the Box, set the cropping modes (four cropping modes are supported: inside/outside of the Box with wireframe and without wireframe respectively), click the "Analyze" button, and then apply the cropping mode to the side of the selected model in the scene. Click the "Analyze" button, then click Apply this Box on the side of the selected model in the scene, and then you can see the scene outside or inside the box alone.
Set the plane range of the layer for profile cropping, three-dimensional display of the internal structure of the model profile.
Operation: Select "Plane Crop", click "Analyze", click to draw three points in the scene, and end the drawing operation with the right mouse button. If the three points are drawn counterclockwise, the data above the plane will be cropped out; conversely, the data below will be cropped out. Click the "Clear" button to restore the model to its original state.
Cuts a quadrilateral on a plane of the model to cut off the data within the quadrilateral.
Operation: Select "Cross Crop", set the width and height of the quadrilateral (in meters), the rotation angle around the X/Y/Z axis, and the stretching height (in meters), and then click the "Analyze" button, and the mouse will change to the state of the drawing plane. When you click on the selected model in the scene, the data within this plane will be cut off. Clicking the "Clear" button will restore the model to its original state.
Cuts out the data inside or outside the range of the drawn polygon.
Operation: Select "Polygon Crop", choose the crop mode: inside/outside the model, click the "Analyze" button, click the starting point, folding point, and end point of the drawn polygon in the scene, and end the drawing with the right mouse button, then the scene within or outside the range of the polygon will be displayed. Click on the "Clear" button. Click the "Clear" button to restore the model to its original state.
The iEarth WebApp supports terrain manipulation, inundation analysis, slope orientation, and contours by selecting the 
icon.
You can set up a pit area on the ground surface, so that you can easily view the situation of the underground scene corresponding to the surface area, such as viewing the underground pipelines.
Operation: Select "Terrain Operation", set "Excavation Depth" in the "Terrain Excavation" area of the expanded panel, and then click "Analyze". Then click "Analyze", draw the excavation area in the scene, right mouse button to end the drawing, that is, it will start the excavation analysis, the side of the pit will show the corresponding terrain of the underground sample cross-section, and the bottom surface of the pit range corresponds to the bottom of the wind appearance.
This function is used to modify the terrain in the area when the model and terrain do not fit well enough, STK terrain does not support terrain operation function for the time being.
Operation: Select "Terrain Operation", click "Analyze" in the "Terrain Modification" area of the expanded panel, draw the modified area in the scene in turn, and end the drawing with the right mouse button, then the analysis will be started. Begin to analyze, draw the area within the scope of the high terrain will be depressed, low-lying areas will be pulled up, and ultimately with the drawing of the plane elevation consistent.
You can dynamically simulate the inundation process of the water level in the specified area from the minimum elevation to the maximum elevation.
Operation: Select "inundation analysis", set the analysis of the elevation range (maximum and minimum elevation, unit: meters), the transparency of the water, the playback parameters (the current elevation (meters) and the inundation speed (m / s)), and then click on the "Analyze" button, in the scene terrain Then click on the "Analyze" button to draw a polygonal area in the scene terrain, the right mouse button to end the drawing, that is, it will dynamically display the drawing area within the scope of the water level from the minimum elevation up to the maximum elevation of the flooding process.
Slope is the angle between the tangent plane and the horizontal plane at a point on the earth's surface; the larger the slope value, the steeper the terrain; the smaller the slope value, the flatter the terrain. And the direction of change in slope is called slope direction, refers to each image element to its neighboring image elements in the direction of the maximum rate of change in the direction of the downslope, indicating the surface of the earth at a certain location of the slope direction of the measure of change. The range of analysis results for slope expressed in degrees is 0 to 90°; the range of slope direction calculations is 0 to 360°, starting at 0° due north, moving clockwise, and ending at 360° back to due north.
You can calculate the slope value of the terrain in the specified area and the direction of the slope surface to generate a slope direction map. The layer to be analyzed must have a normal terrain, STK terrain does not support this function for the time being.
Operation: Select "Slope Direction", specify the region to be analyzed (support: specify the region to be analyzed and all regions to be analyzed), the slope interval to be analyzed (minimum and maximum slope, unit: degree), the fill style (support: show fill color or arrow, or both) and transparency of the analyzed region, and then click the "Analyze" button, draw a polygonal area in the scene terrain, the right mouse button to end the drawing, that is, it will show the drawing area within the scope of the terrain of the slope of the slope of the direction of the situation.
Extracts contours for a specified area of the terrain based on the image element values of the terrain data. The dataset used for contour analysis must be a raster dataset such as DEM or Gird.
Operation: Select "Contour", set the elevation range (maximum and minimum elevation, unit: meters), contour distance (distance between two adjacent contour lines, unit: meters), line fill color of the analysis result, and fill mode of the result (support contour fill, isotropic fill, isotropic surface fill, and no color table), and then Click the "Analyze" button to draw a polygonal area in the scene terrain, right mouse button to end the drawing, that is, it will show the results of contour analysis of the terrain within the drawing area.