Once a Level AI run is complete (check by looking at the Status Pane) you can pull the results back into your DWG. Do this by clicking the Results button.
Level AI results brings in the road profiles and features lines for all of the elements in your model. E.g. for grade breaks (walls / batter slopes) it will bring in the top and bottom as feature lines.
There are different types of results that can be generated, a pop-up when you hit Level AI results button will tell you which result type you are dealing with:
Result Type | Description |
Min Design | This is where the minimum levels that meet all of the input engineering constraints is the best design - this means there is net fill import required for the site (unbalanced) |
Max Design | Same as min design, but requires maximum allowed levels for the site and means there is net cut export required for the site (unbalanced). |
Balanced | The design has balanced and run through a number of cycles attempting to get to net zero balance. You can adjust the Level AI settings to run more cycles or fewer (ie if want a result returned quickly) |
Non Viable | This means more than 10% of the site is non-viable. Review the overlays to determine where the design needs to be modified to get a viable run. Note you are not charged for non viable runs if what-if mode was disabled. |
Non Viable 'What-if' mode | If the 'what-if' mode is enabled for your Level AI run it will run your design through multiple scenarios to attempt to achieve viability. See below for more details on how to interpret and use results to get a viable design in your next iteration.
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What-if modes
What-if mode is a great way to get an initial design and visualise a potential model solution and then take potential grade breaks and add them to your model for a subsequent run. What-if mode only runs if the setting is enabled:
You can also specify how POTENTIAL-GRADE-BREAKS are placed on the site depending on your requirements.
What-if scenarios are run in priority order:
What-if more walls - this wraps the lots in grade breaks leaving a space for the driveway (varies height starting at 60 feet and rerunning with lower heights until viable)
What-if high walls - this removes height restrictions on walls
Increased lot grades - grade restrictions on lots are removed and lots allowed to grade up to 33%.
Review Overlays
The following review overlays are output along with the results. Use the Review Layer to toggle various overlays on and off. Toggle the Review Layers button to toggle all of the review layers on and off.
Overlay | Description | Example |
Range Design | This raster overlay shows areas of the site that are non-viable. This can be previewed while your Level AI run is going via the Job status pane. Red means more non viability, blue means a small amount of non-viability. Viability is the difference between the Maximum and Minimum Envelopes of the design. | 
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Min Design | This is a raster overlay showing the levels of the minimum allowed design that meets all engineering constraints. It is off by default by can be enabled in the Allsite Review Layer filter group. | 
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Max Design | Same as min design overlay, but for the maximum allowed design that meets engineering constraints. |
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Cutfill | An overlay showing the amount of cut and fill required on the site. Blue means fill and Red means Cut. |
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Interpreting Non Viability
The Range Design overlay is key to interpreting the design, this is the difference between the minimum and maximum design envelopes - areas where it is negative (highlighted by color range) show that the maximum possible design surface is below the minimum possible design surface.
It is good to inspect the overlay and see areas where the design is non viable even on balanced designs (as some areas of non-viability can affect the design).
Common causes of non-viability:
- Grade restrictions on the site don't allow for handling of grade across the site (e.g. lot grades, road max grades, lack of grade breaks).
- No grade breaks at front or sides of lots (steep sites) so road can't grade up to it's maximum and thus cannot meet grade requirements for site.
- Grade breaks (ie wall / batter slope) not allowed to go high enough so can't deal with grade across site.
More information on diagnosing non-viability is provided here.
Contact our support team if you have questions about interpreting non-viability of one of your designs.