Tuesday, 13 October 2015

Trimble Link Civil 3D road export critical points of interest.

A Civil 3D road can be exported to RXL only if a Corridor surface has been created.
But Trimble Link does not in fact export triangles !
In fact it uses this surface for two purposes.
First is to get the feature lines and or links that compose the surface.
Second is to get the area that the surface is limited.


The second purpose is critical for two reasons.
1. User may have not created a boundary. So useless surface triangles might exist. This is not a problem since exporting does not use any triangle at all.
2. User may have created a boundary that does not cover the whole of the expected corridor surface area but a part of it !!! So Trimble Link reports a text message to indicate those areas by station values. And finally those areas are omitted !!!


There are some very serious limitations about Trimble Link and they occur because of the logic Trimble Access or Survey Controller works.


There is always at least one side. Left or Right. It is not possible to have a road that it is not connected to axis. Axis can not be far away out of the road !!! Links always start from the axis !!!


It is not possible to have a continuous lane that crosses an axis !!! If a lane includes an axis then Trimble Road Link cuts the lane in two pieces. One for the left side and ne for the right one.
Also if lane does not pass through axis at profile elevation then for both sides a code named "Constant" vertical element is created from axis profile elevation to intersecting lane position.


Another serious limitation has to do with slopes. User is forced to select whether to consider last element for left and or right side as a slope. This is completely idiotic. There are cases that some cross sections do have slopes and some others do not. There should be an option to select codes by Link and or Feature Lines to consider them as slopes.
Most worse if a side has only one element then this is considered to be a slope one so user has no idea where this element ends !!! Totally crap logic !!!
Another one serious limitation has to do also with slopes. Say a cross section has a design catch daylight cut for 1:3. If side slope is checked for this side then cut slope is set to 1:3 but also fill slope is set to the same slope no questions !!! So if on site the real case is a daylight fill and a 2:3 is the desired slope then user must be carefull so that he manually change the slope.
There should be an option for the user to select to have a "Do not assign non existing slope" or "Default fill/cut slope to use if not existing in Civil 3D".
In case there are not a lot of cross sections i use MS XML editor to manually alter the Slope elements of the exported RXL file. If only i knew that new Trimble GPS does not support Carlson SurvCE...




Leica RoadRunner is not limited to anyone of those above. It can also accept points that create a closed shape !!!


Leica RoadRunner uses only one way to export corridors. Feature lines. In latest version (Civil 3D 2016) it is possible for the user to select which (available-meaning checked in corridor parameters) of them to export. But it is not possible to export parts of cross sections using boundaries.


My choice...Leica RoadRunner. Not the best. Not even close. But compared to Trimble Link then...no second thoughts.


Soon to enter some images to graphically represent the above.

No comments:

Post a Comment