Alternative reference surface for pipe network

[DmitriyZagorulkin]

For example, this situation:

We need to specify a pipe covering from the surface. But at one end of the pipe - this is the project surface, and on the other - the existing surface. The idea is to be able to set an additional surface for the network (network part). In a place where there is no basic reference surface, data on the alternative surface will be taken.

[joantopo]

And why you don´t paste both surface in a single surface?

This topic would be similar than multiple surfaces for a surface target with the criteria "nearest/furthest" like offset or elevation targets can do.

[DmitriyZagorulkin]

Yes, now we put both surfaces in one surface. We give it the name "Total" and use it as a reference surface for networks. But this is a workaround, it is not natural for designers. We create an additional object that is not used anywhere else in the drawing, except to set the desired position for parts of the network. This surface is not always correct. Here is an example:

Target with the criteria "nearest / furthest" is bad. For example, the surfaces can be arranged like this:

If Autodesk succeeds in implementing this idea and making the property for the part of the network "the current target surface", then we can display the name of the target surface in the label for the pipe or structure. We can create a table in which there will be a column "current target surface" and calculate, for example, how many structures are placed in the area of ​​the project surface, how many structures in the area of ​​the existing surface.

[spear_kevin_pe]

Not a bad idea. I would not consider pasted surfaces as a workaround. I've used that concept for many things in a project cycle, including for pipe networks.

To address your issue when the "total" surface doesn't work, we have to look at how we are creating the total surface. 

1. Composite Surface - pasting multiple surfaces into a new blank surface will re-triangulate from the edge of smaller surfaces to the data in the larger surfaces. In other words, the smaller surface boundary acts like a destructive hide boundary. Then the smaller surface data is added and results in re-triangulation.
2. Use project surface boundary as non-destructive bdry - using the same process above, we would add the EG to the TOTAL surface first. Then extract the boundary of the project surface. Add that to the TOTAL surface as a non destructive hide boundary. Then paste the PROJECT surface. 

Again, none of this a workaround, it's a process driven by the results you need. Civil 3D is a collection of processes you string together to get your finished design. How you get there is up to you, not Civil 3D. 🙂

[scaldwell73]

I was just getting ready to post the same idea and then popped up. I use a hybrid surface (proposed pasted onto existing) with auto-rebuild turned on since we use data references. I was thinking you would set a hierarchy for surfaces for creating pipe networks. Proposed would be at the top of the list but if you get out of it's range then it would look at the next surface in the list for elevations.