Most of the time I create a proper TIN up against the biilding. The surface inside is then removed. I have done it other ways for different applications.
I enjoy doing diverse work, and there is one constant. Those who insist they know the only proper way to express survey data rarely make it through the first cut. Our data is used for a lot of different things. Sometimes the customer really does know what they need...
I have been a cartographic drafter for some 45 years. In all that time the basic rule is that contours NEVER go through buildings. NEVER.
Contours for a normal topo never appear on loading docks or other elevated features.
Take a careful look and understand what a contour line is supposed to represent. Re-read the definition of a contour.
Dashed contours going under a building? Base on what data?? Dashed contours are legit as "approximate contours" and are generally used in photogrammetry where the stereo operator cannot clearly see the ground and are generally swags based on all available data.
Stop the contours at the edge of the building. What if there is a basement? What if there isn't? It's kind of like trying to contour an aerial walkway. Ain't no such animal.
Create a void area around the building perimeter and don't run your TIN/contour lines through the building. I agree that running your contours through buildings/walls is sloppy work. Running contours through buildings is the same as running them over/through waterways you have not surveyed. In my opinion, if you do not have hard elevation shots in that area then you need to void it from your contours.
Don't show them inside the building. It looks stupid.
I don't put contour lines through existing buildings.
callen, post: 333054, member: 6231 wrote: I have have had several engineers/techs indicate that autodesk civil 3D software can't understand a hole in the surface for design purposes, and they would. Have to "fix" the provided surface to use it. Traditionally I was taught to stop surfaces at buildings, or areas not surveyed, not to fake it in. I've not argued so far but seems like either a software flaw or the users not understanding it. Others have never mentioned it.
It could be an issue figuring dirt quantities in some cases (bi-level building) if the arent understanding the process.
Those engineers/techs do not know what they are doing. Our engineers do this all the time.
Dan Patterson, post: 333218, member: 1179 wrote: Don't show them inside the building. It looks stupid.
This is the best answer!
TickMagnet, post: 333084, member: 4378 wrote: Some cities I work in have a slope calculation formula that asks for 'total length of all contours' as part of the formula
(to calc the maximum development area for the new construction) (California)On these projects I let the contours run thru the buildings and and a note "contours inside of buildings are for slope calculations only"
otherwise I trim them at the building footprint
Wouldn't the calculation be more beneficial to the developer if the contour ran around the wall perimeter of the building as it should?
The foundation of my career is my time in the military. I understand where you are coming from. The major versus index thing makes my head explode. At the same time I've added 30 plus years of experience working in a variety of disciplines. I can say with certainty that a 'proper depiction of contours' is not nearly as rigid as you describe.
I've done sound contours, contamination contours, light contours and more. One of my jobs was a remediation and retrofit of an auto plant. There were three sets of contours in every building. The entire point of the survey was to generate them.
For the run of the mill design topo I agree, contours inside the building serve no purpose and give an appearance of laziness. There are times they belong there...
callen, post: 333054, member: 6231 wrote: I have have had several engineers/techs indicate that autodesk civil 3D software can't understand a hole in the surface for design purposes, and they would. Have to "fix" the provided surface to use it. Traditionally I was taught to stop surfaces at buildings, or areas not surveyed, not to fake it in. I've not argued so far but seems like either a software flaw or the users not understanding it. Others have never mentioned it.
It could be an issue figuring dirt quantities in some cases (bi-level building) if the arent understanding the process.
This is categorically incorrect. With every version of AutoCAD I've used (starting with R14 and currently on Civil3D 2015) you can easily eliminate the contours through a building (or any other area) with a couple quick steps.
I always hide the contours through my building as my field data has no information indicating what the elevation of the dirt under the building is. For the floor elevations, if we are asked to provide those, I take a few observations and typically add a note for the finished floor elevation of the building (to the nearest tenth) if it is reasonably level. If it isn't, I'll typically note that the floor is uneven/irregular and show some of the spot elevations measured.
But the idea that Civil3D "can't understand a hole" is wrong and shows that the person making that statement doesn't know how to use the tools they have.