Perspective Rendering using SketchUp, Google Earth, and Civil3D

SketchUp Pro
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I’m working on a few site renderings using a combination of tools, including SketchUp 2018, Civil3d 2016 (2013), Google Earth Pro, and Photoshop, but I am having trouble achieving a final product due to software compatibility issues and/or coordinate and datum synchronization. My goal is to generate a model that can be imported into Google Earth so that the proposed features can be realistically visualized within the existing topographic context from a number of various perspectives. A general summary of my workflow follows:

  1. Develop proposed site layout in Civil3D over an existing conditions GIS/Land Survey basemap projected in the GA East State plane coordinate system (NAD83).
  2. Prepare individual 3D models and components in SKETCHUP (to scale, and customized to match dimensions determined in layout).
  3. Export each proposed feature from SKETCHUP to “.3ds” file, and import each .3ds model into CIVIL3D, convert to a “.dwg” file (Block), and insert into initial CIVIL3D layout drawing at the precise XYZ coordinates.
  4. Export 3d Objects from CIVIL3D to GOOGLE EARTH using the “Export KML” utility in CIVIL3D using designating the coordinate system.
  5. Prepare additional individual 3d models to be used for context (vehicles, trees, people, utilities, etc…).

***Everything works great up to this point, but I ran into trouble once I began adding contextual features (Cars, trees, etc…). Basically, Google earth struggled to render the more complicated 3d warehouse components I had chosen and ultimately converted to blocks in CAD (using the same process described in the previous steps). Therefore, I changed my approach, and attempted to generate all the contextual elements directly in SKETCHUP and utilize the Geo-Location tools to determine the approximate placement of each object and tried exporting the entire model to GOOGLE EARTH as a separate “.KMZ” file/layer. While I the components appeared in the correct horizontal position, they were floating 20-30 feet above the surface. Despite several experimental attempts to correct this, I have been unable to successfully get these components “clamped” to the ground plane.

Please let me know if there something I can do to resolve this issue?

Thanks,
Wright

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You will want to leave the model components on the “modeling ground plane” (which is the SketchUp XY plane.)

Go to the SketchUp Extension Warehouse, and get a SketchUp attribute editor plugin, such as:

THEN (after installing the plugin,) use it to tweak the elevation attribute that is used (exported to KML file in the KMZ archive,) for the attribute dictionary named: "GeoReference" that is attached to the SketchUp model object.

You’ll see the 3 translational X, Y, Z attributes that locate the model in Google Earth.

(The values are in inches I believe, but I do not remember what the datum is for X,Y. I think the Z datum is sea level, as there is a switch for modeling shipwrecks that uses depth below sea level or simply the ocean bottom at the X,Y coordinates.)

So, you perhaps want to subtract 30 * 12 from the "ModelTranslationZ" attribute value and try another export. … Repeat tweaking until you get the objects on the topo surface.

ADD: By the way, this is likely caused by inaccurate terrain elevation data in one or the other of SketchUp or GE. Ie, one of them is using too coarse of a terrain mesh.

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Also, in Google Earth, do you have the Legacy 3D buildings layer turned on? In Options/Preferences, in the Terrain section, you’ll probably want to uncheck the “Use 3D Imagery box” to return the terrain to the level that SketchUp is more likely to use.

Let us know if those suggestions helped! And welcome to the Forum!

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