Grading with Feature lines

[longislandengineeringllc]

I am looking for any tips or suggestions when grading with feature lines.  I am regrading a large, several hundred acre, mine site for reclamation.  I am breaking my surfaces up by phase, so a single surface does not become too large or complicated.

Currently C3D is hanging when trying to perform an infill.  When I execute the infill I get the green diamond and then C3D just chugs away and nothing happens.  Ever.  I end task.  audit.  purge.  recover.  audit purge.  No help.

The area I'm trying to infill is large.  40acres (not sure because C3D is current stuck again)  The boundary of the infill is made up of several different feature lines that connect to make a enclosed area.  I wasn't sure if that method would work, but I tried it on a smaller area and had good success.  I was even able to grade to surface at 3:1 in the smaller area.  But for some reason C3D is on a long break from productivity.

Any thoughts or steps that you like when grading large areas?

PS.  How long do you let C3D hammer away before you END TASK?

Thank you!

[tcorey]

You gotta break the grading down into smaller sites. It would be nice if Civil 3D could handle infinitely large data sets, but that's not reality.

Maybe this is something Autodesk could add to their cloud offerings, apply infill to a very large set of gradings. The problem is, how many would use it?

[glyons]

I would think that it's not so much an issue of the size of the surface in terms of area, but the complexity. How many vertices do the feature lines contain? Elevation points? Would it be possible to weed the feature lines in order to simplify the surfaces?

I routinely have surfaces that large or (much) greater* without any issues w/C3D hanging. That said, I avoid using grading object as much as possible because of their well know stability issues. When I do use grading objects, I keep them segregated in their own file as a component surface and dref/paste that into my overall surface.

*Edit - I had the 40 acre number stuck in my head, not several hundred acres...   although the principal holds.

[jmayo-EE]

"How many vertices do the feature lines contain? Elevation points? Would it be possible to weed the feature lines in order to simplify the surfaces?"

I would bet this is the issue too. Weed it. Feature lines get scary & highly crash worthy with thousands of vertices/ElvPoints. I would also bet this is not a real crash and if you left your pc running overnight you may have the infill by morning. 

Can you just add the feature lines to a surface instead of grading an infill? Result would be the same.

Performance would improve with 3d polys instead of feature lines as well.

[Neilw_05]

I have encountered situations where C3D would not create infills even though I know the region is closed. I've given up on using the C3D grading tools for anything other than small residential sites. They are too unstable. I have the option to use another software product to do grading but since you likely don't have that option you will have to get by with the tools you have. That said, you might want to try reducing the infill area by adding some featurelines across the open area. As long as they are in the same site they will acquire the elevations of the end points. Then add infills to the reduced areas. Keep working your way across the open areas like this until you find a spot that won't infill. You then have narrowed down the problem area and can investigate. 

[Joe-Bouza]

I concur with the vertice count. I will als add that if C3D is chugging / hanging with a grading  that I would abandon ship. An I mean that entirely. 

Personally I would not hang my hat on using grading for something that large. Specifically the use of Projections from long long long feture line with a bazzillion verts.

I would go corridor with Feature line baseline and assembly with Markpoint for linear breaks, Link(bla bla bla) and so on. You still have to minimize verts/ elevation

I don't mean to sound harsh but Grading are going to kill you when you least can afford it ( usually when it is time to plot deliverable)

I am not saying don't ever use grading. Use them to feed your model not as an integral part of your model

[longislandengineeringllc]

Thanks for the comments everyone.  I've been out in the field quite a bit so it took me a while to give it a go.

So the feature lines have very few vertices.  Maybe only a dozen or so.  I've ran into that before with the huge vertices count.  I did get the grading to work.  I deleted the grading I had and then performed the grading functions in a different order.  Then tada it worked.  

Are there other grading tools that you recommend for large sites?  These are not typical CIVIl sites.  I am actually not very good at corridors.  I like the grading objects and they tend to do what I want, but extremely painful sometimes.  I'm not sure how I would set up a corridor to grade a 40 acre mine phase with with four sides sloping inward at different slopes and the bottom draining out towards a single discharge point?  

Thanks for the help everyone! 

[Joe-Bouza]

Same way with less volatility. 

[Neilw_05]

But a whole lot more set up time and dealing with transitions, overlaps and parts that don't behave. Then you are locked into using the cumbersome corridor editing tools to edit the model  ("assemblies and targets and regions oh my").