Fault Surfaces in Earth Volumetric Studio

Feb 7, 2017 in Tips and Tricks

There are normally two reasons to create fault surfaces in EVS.  We either just want to display them, or we want to use them to create fault blocks as part of a more complex geologic model.  When we create fault blocks, we are using the surf_cut module and the fault surface is input to the right input port.  There are three main cases to consider with respect to the creation of fault surfaces: 1) Planar surfaces.  A planar surface is a surface which is flat.  It can be oriented in any way, but is has no curvature, bumps, etc.  This type of fault if very easy to create with the create_fault_surface module.  However, you can also cut any 3D model using the “cut” module to create a fault block. 2) Non-planar surfaces created in EVS.  There are two cases here.  Single-Valued and Multi-Valued surfaces Single-Valued or simple surfaces can be created using krig_3d_geology, krig_2d or scat_to_tin using x-y-z points formatted as .GEO, .GMF or .APDV files.  This is the easiest way to create more complex surfaces which have only ONE Z coordinate for any X-Y location. Multi-Valued surfaces are surfaces which which have TWO or more Z coordinates for any X-Y location. Some simple examples would be a sphere or a tube (pipe). Some are easily created in EVS.  For examples it is easy to create tubes of constant or variable diameter with the tubes module, and these can be used to cut tunnels through geologic models. However, in general the creation of multi-valued surfaces is a very difficult process since traditional estimation methods such as kriging, IDW, splining, TIN, etc. cannot be used.  In some cases it is possible to find a coordinate transformation where the surface would not be multi-valued. For example, imagine a cross-section through a multi-valued fault surface below.  The red line shows where this surface is multi-valued.  If we rotate counterclockwise 90 degrees, this surface is no longer multi-valued and could be created using any of our traditional methods.  All we need to do is rotate the data, create the surface and then counter-rotate the resultant surface back.  We can rotate the data using transform_field, create the TIN (or krige, etc.) , and then rotate back to the original coordinates.  Be sure to use the same center of rotation in transform_field. To confirm everything is correct, we check it against the original data.  Sometimes the angle needed is not 90 degrees, but since you don’t need to do the math yourself, it doesn’t matter.  In the case below, it would probably be better to use -75 vs. -90, since the “rotated new” left edge is nearly vertical. However:  Sometimes, there is no set of rotations that will work, as in the case of a sphere.  3) Multi-Valued surfaces created outside of EVS.  Though we don’t always provide ways to create every possible type of complex multi-valued surface, if you do have a complex multi-valued surface that was created in CAD software or by some other method, it can still be used in EVS as a fault cutting surface.  There are just a few simple requirements: The surface can be composed of triangles or quadrilateral cells.  When these cells are defined, the order that the cell’s nodes define the cells determine the normal vector of...

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Volumetrics Study: Studio vs. MVS

Jan 18, 2017 in Tips and Tricks, Training

Prior to the formal release of Studio, we did a comprehensive volumetrics study because we were making significant changes to both volumetrics and subsetting (e.g. plume) modules in Studio.  In that study we looked at our new Studio algorithms compared with MVS as a function of grid resolution. We’ve always known that as you increase the resolution of your model, the accuracy improves and we always see volumetrics results approach an asymptotic “theoretical” value as the grid resolution is increased. Our new algorithms in Studio work dramatically better than MVS, but we didn’t make a big deal about it, primarily out of concern that by saying that Studio is much better, we could be misconstrued as saying that MVS was somehow WRONG before.  In reality, everything we do (and by reference, everything you do with our software) is geostatistical by nature.  It is a best estimate.  And usually it is only a fair estimate because of data quality. In our study we focused on Chemical Mass (not plume volume) of the entire model, as well as X, Y, Z CG and Average Concentration.  If you additionally consider subsetting (plumes) they will effectively decrease the model resolution since the subset upon which you are computing volumetrics is a portion of your total model that has a lower effective resolution.  The higher the subsetting (plume) level, the lower the effective resolution and the poorer your results may be. The tables below summarize our results which are also given as graphs.  For both Studio and MVS we did the calculations with and without Adaptive Gridding (AG) for the total number of nodes ranging from 30,000 to nearly 8 million.  For all cases, we are computing volumetrics on the entire grid without any subsetting.   Both Studio and MVS reported exactly the same volume for the full grid which was 350,950 cubic meters.  This was not affected by resolution nor by adaptive gridding. In our study, there were very minor if any differences in volumes or plume volumes between Studio and MVS.  The biggest differences seen were in the computation of Chemical Mass and those parameters derived from chemical mass. The first, and perhaps most surprising observation of our study is how little impact (improvement) Adaptive Gridding makes for either MVS or Studio.  Adaptive Gridding does ensure that the data extremes in your 3D gridded output will better match your input data, but with respect to improving volumetrics accuracy, your time is better spent kriging a finer grid than waiting for Adaptive Gridding to finish.  The reason for this is that Adaptive Gridding refines the grid in localized areas around your data samples, but does not improve the grid globally.   As you can see, the Studio volumes are always higher than MVS, but are within 1-2% of the asymptotic value at virtually all grid resolutions.  For MVS, the volumes can be 20-25% low when the resolution is too coarse, but both Studio and MVS approach the same solution at high resolutions.. Average Concentration is derived from Contaminant Mass, and therefore is equally affected by the differences in accuracy as can be seen in the graph above. The three graphs below show the deviations in the CG or centroid of the contaminant mass in X, Y and Z.  A similar affect is seen here where Studio is markedly better at...

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Modeling of Karst Geology with Caves

Jan 17, 2017 in Tips and Tricks

One of C Tech’s distributor’s in China asked us to explain how Earth Volumetric Studio could be used to model Caves. The most straightforward approach is to use indicator kriging (e.g. indicator_geology module) and treat the cave as as if it were another material in the site lithology.  The video below takes this approach.  You can also apply adaptive_indicator_kriging to stratigraphic geologic models.  In this way, if you have a site with stratigraphic geology, you can include a cave based on lithology data within the stratigraphic layers. Other approaches are to model the cave as a volumetric excavation within any type of 3D volumetric grid using either: Binary lithology (values of 1 inside the cave and 0 outside the cave).  You would format the binary data as an APDV or AIDV file and use krig_3d (turn off log processing),  or Using a closed surface created outside of Earth Volumetric Studio (such as LIDAR) and then using surf_cut I hope that this instructional video will be helpful.  The application shown here will be included in the next release of Studio Projects. Reed D. Copsey,...

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C Tech’s Twitter Feed is the Exclusive Source for Free Training

Dec 23, 2016 in Announcements

Our Twitter feed is the only place you’ll find our announcement and registration info for the free online class on how to use our new texture library when we release 2017.1. Go to @CTechSoftware

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Video on Cut-Fill Optimization in Studio using Python Minimization

Dec 2, 2016 in Tips and Tricks

We have posted a new Tips & Trick on Cut-Fill Optimization in Studio which uses a Python script to quickly converge on the optimal elevation for an excavation surface so that the amount of fill needed exactly matches the amount of material that is cut. The video is here:  

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Full list of Recorded Online Classes now Available

Oct 13, 2016 in Announcements, Training

We have updated our Online and Recorded Classes page to reflect the full list of Recorded Online Classes which are now available for rent.  These are the meticulously edited video recordings of the online classes which were recently held and reflect the functionality of the current version of Earth Volumetric Studio.  The rental of each class includes the additional materials, data and/or applications which were generated during the class, and are provided by download. Introduction to Earth Volumetric Studio: 4 parts: 3 hours each Migration from MVS to Earth Volumetric Studio: 2 parts: 3 hours each Advanced Lithologic Modeling Video Class: 3 Hours Advanced Gridding with krig_3d_geology Video Class: 1.5 Hours Time Domain Data Video Class: 3 Hours Python Scripting in Studio: 3 Hours Advanced Variography in krig_3d: 3 hours Enterprise License (Premier Program) customer with available training credits may use those credits towards these classes.  All others must arrange payment in advance before the URL and passwords are issued to access the recordings.   All students are required to complete the online video training registration form and submit it to sales@ctech.com in order to register for one or more classes.  ...

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Major Release of Earth Volumetric Studio 2016.9

Sep 27, 2016 in New Releases

Earth Volumetric Studio 2016.9 has been released and is available for immediate download.  New sample projects and an updated PDF Converter have also been released. We certainly can’t claim that this software release rivals the August release which was the formal release of Earth Volumetric Studio and our first 64-bit software version. However, it does offer some very important features that will affect virtually every user and therefore, I encourage you to take a few minutes and read this email carefully so you understand the important changes that we’ve made.   3D Publishing: For those who have embraced 3D Publishing to either 3D PDFs or Sketchfab, you are almost certainly familiar with the texture_colors module and the fact that it is essential to creating good 3D PDFs and that has been incompatible with Sketchfab. You’ll be surprised then to find that we have deprecated texture_colors. However we have a great reason. Virtually all modules in Studio now create output that uses texturing for coloring. This means that the coloring challenges for 3D PDFs are gone. For those of you who haven’t used texture_colors before, it provides significantly improved rendering of surfaces, especially those with high gradients. The changes we have made will make everything you do look better. Sometimes it will be a subtle difference and sometimes dramatic. The greater news is that we’ve figured out how to make Sketchfab support textures, including texture_colors type coloring, textured geologic layers and aerial photos. This means that Sketchfab and 3D PDFs are virtually identical in their ability to create 3D model content. You’ll also find that colored lines like axes and streamlines work in both 3D PDFs and Sketchfab. There are still limitations to both of these media, but both are dramatically improved. New 3D PDF Converter Required: With these changes, a new 3D PDF Converter was required. It is on our website for download and everyone with current maintenance (all Premier customer are automatic) can install it and it should run without any license updates from C Tech. If your PDF Converter license is out of maintenance, this new version will not run, but you can contact sales@ctech.com and we can provide a quote to bring your license up to date. Please note: VRML files created with this version will not convert to 3D PDFs with the older version of the 3D PDF Converter. New Publish To Sketchfab exporter: We now provide the functionality to directly publish to Sketchfab. This will take care of ~90% of the details that we taught in the 3D Publishing Class for you automatically, such as: Properly setting the view in Studio Unlocking the background Turning off all items in the 2D Overlay including Forward Facing Fonts Creating the VRML File with appropriate settings Logging into Sketchfab and uploading the file Setting Sketchfab background color to match Studio background Optimizing Sketchfab settings to match Studio lighting, colors, etc. Thank you, C Tech Development Corporation Software Sales Department Phone: +1 (941)...

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New Training Videos: 3D Kriging and Advanced Gridding

Sep 6, 2016 in Announcements, Training

We have just posted two new series of public training videos for Earth Volumetric Studio. The first series is on 3D Kriging in three parts: Part One focuses on krig_3d, some of its basic properties and discusses the limitations of its flat-topped rectilinear gridding in anticipation of Part Two. Part Two demonstrates how easy it is to incorporate krig_3d_geology when doing 3D kriging so that your grid is conformal to site topography and/or includes site stratigraphy. Part Three introduces draw_lines and triangulate_polygons to create a user-defined area, which we then use area_cut and intersection to subset the model to show the region inside or outside of that area. Finally, we explore volumetrics and its important settings to ensure that volume and mass analysis is performed correctly. The second series is on Advanced Gridding: Part One introduces krig_3d_geology’s Finite Difference Gridding option which provides a very flexible means to create a rotated rectangular 2D grid with complex cell size distributions. This video covers it basic functionality and is recommended for all users. Part Two continues Part One to add area_cut, polyline_spline and triangulate_polygons in order to create a grid that is confined to a region which closely conforms to the concave hull of a riverine dataset. It is recommended for advanced users and those needing more control over the areal extents of their models. Both video series are available on the public Training Videos page....

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Stratigraphic Geology Training Video Series Posted

Aug 24, 2016 in Announcements, Training

We have just posted a new series of four training videos on modeling Stratigraphic Geology.  The first three cover rather basic topics related to the creation of stratigraphic geologic models, but the fourth and final video in the series tackles the more complex horizon_ranking module and how to use it to control hierarchy when you have intersecting stratigraphic horizons. All four videos are available on the public Training Videos page.

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New Training Video: Animation in Earth Volumetric Studio

Aug 22, 2016 in Announcements, Training

There is a new addition to the Earth Volumetric Studio Training Videos. The Animation in Earth Volumetric Studio video demonstrates the basic procedure for creating animations. We begin with a beginner application and make some simple modifications to it before learning the step-by-step procedures for creating a high-quality AVI which is included (3 times) at the end of the video.

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