Displaying cross-sections on a web page

Question

I'm looking for inspiration and possible tools on how to display cross-sections on a (dynamic) webpage. More specifically I have to show on these cross-sections how underground pipelines are located compared to the surface. Apart from the 2D information on the surface (high resolution) we will also have access to lidar data of the surface around these pipelines.

I'm basically considering two paths. One is to make a true cross-section, like eg this example:

Another option would be to create a small strip of land, a bit like this image (but with a much more boring look, but and showing the depth of the pipelines also. . This has the advantage that the surrounding terrain is also shown, which is useful as the position of the pipelines is not always very precise.

Although I have some ideas on how to create the first one (basically making a projection along the transect), I wonder if any tools exist that could create images like the second one. And in general I'd be interested to know if anyone has already knows of (or made) similar applications.

Answer 1

To create cross section:

• use ArcGIS, MapInfo, etc. with point XYZ data projected on either south-north or east-west plane
• or use dedicated geological software to create the section (Geosoft Target, Leapfrog Mining, Rockworks, Datamine Studio, etc.) Might require some post-processing to manually add or adjust labels and text

To create 3D topo/subsurface slice as depicted on the image you supplied (BTW that appears to be a hand-drawn image which is still not uncommon given how much work has to go into making a dynamic 3D model):

• use GIS data to create basic 3D model in ArcScene (ArcGIS 3D Analyst) or similar. Export model to dedicated 3D Modelling software for finishing touches.
• Export 3D model to file type suitable for interactive use with your website
• Or create a video animation from your 3D model (static but easier)

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To expand on the above:

As you have implied you can make a cross section by projecting XYZ point data on either the south-north plane or the east -west plane then manually digitize/symbolize down-holes and add other graphical components. I should pint out that this method is extremely time-consuming and that once the section location is set, changing means recreating the entire section again. Something like that can be done in ArcGIS (which is what I use) but I've seen it done in MapInfo and I am sure other tools where you can re-project XYZ point data by simply re-mapping the XYZ coordinates to simulate a sectional view. I still create simple East-west long sections in ArcGIS using this technique.

Here is an example of a section created with ArcGIS:

A far easier way to create a cross section from geology drill data is to use a geology/drill-hole management software such as those mentioned above. Depending on which software is used you can easily (or not so easily depending on the amount of data) slice and show subsurface data in any way imaginable. The only issue with this approach is that it typically requires some post-processing; adding text and labels, etc. However the benefit of creating sections in any location, dip, plunge azimuth relatively easily makes this approach worth considering. Changing section location dynamically is far less work then using the XYZ -re-projection method above.

Example of section created in Geosoft Target:

Example of section created in Leapforg Mining (3D features can be exposed in any way, slice, front removed, back removed, etc.):

That concludes sections. Let's talk about the nice 3D image you posted. As I already mentioned I think it might have been hand-drawn although it could have been created as a dynamic 3D model and rendered to make it look hand-drawn which is commonly done with 3D Interiors, etc. Most renderes are purchased (some are free) separately or as plugins to existing software. (i.e. Kerkythea for Sketchup = both free) You almost always need a renderer of you want your model to look photo-realistic or hand-drawn.

The easiest way to create a 3D model similar to the one you posted is to either draw it from scratch in say SketchUp or use SketchUp to alter an existing simpler model that you have created in a GIS. It is also possible (but not easy) to create the entire model in ArcGIS with 3D Analyst but there is no straight forward worlflow for that. There are also no renderers I know of to make ArcScene render photo realistically. What you see is pretty much what you get. Here is something that was created in only ArcGIS without using any other software: Surface renders pretty well in ArcGIS as well. Here is a random 3D surface:

To create a model like the one you want I would start in ArcGIS and create the basic surface, subsurface and water as multipatches. I would then export the multipatches (must be closed) to Callada and import to SketchUp where I would add detail and texture.

As for making the models interactive on the web I will not be of much help but i know you can export to VRML from ArcGIS but you might have to correct textures and transparencies. You can also export to the same format and many other formats from SketchUp Pro (3DS, AutoCAD DWG & DXF, FBX, OBJ, XSI, VRML)

Hope this helps.

Below are some examples of 3D models created in ArcGIS then finished in SketchUp: