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I was thinking about the BIM abilities of bricscad, which I know little about.
I have seen how revit and other progs model buildings, but not a single example of a program that understands how civil engineering BIM objects should be.
That idea of how they "should be" could go a lot of different directions, but what I am referring to is roads and pipelines. I do not mean things like pump station buildings.
I am also not confused about calling 3d things as BIM. BIM objects must contain the industry defined design data required to show in 3D, but its the data that is the part you need to get right to have useful things.
People that do civil design for a living, know that we use a thing called an alignment for linear design. An alignment consists of 2d lines and arcs which define the position in the xy plane (plan view), and a set of lines and parabolic "vertical curves" that define things in the Z axis (profile).
Then we combine those two things to know where something like a road centerline or pipeline invert sits in space. Sometimes we involve another alignment for when the profile is defined along some construction centerline, then projected out to the real, somewhat parallel, location. The data and math are simple though. We do not have native objects like a spline or something, that show the 3d thing. Its always tessellated with a bunch of little straight segments.
Then you add in things like manholes and other structures at certain stations (2d distances from the plan view start of the alignment), as well as pipe diameter start/stop locations. Roads are similar, but much more complex. Roads involve several alignments tied together with cross sections, they are a beast and even involve areas of arbitrary curvature we model with 3d lines floating in space that help control the surface created for the road. How you contain that data is something to be discussed, as it involves compromises.
I'd at least like to see a pipeline/conduit BIM object though. Autodesk did theirs wrong, so the dwg industry suffers from lack of 3d utility models.
Grading is another beast, and is similar to a road with sections and all. We usually make a triangulated surface to model it, which is dumb and non-parametric, thus not BIM. The lack of real BIM objects on the civil side has led many to start calling anything 3d as BIM. They also make heavily compromised things that can take the shape of pipelines, but are not based on the plan and profile data. You must have the original data contained or the editing becomes ridiculous.
We did tools for pipes that use the alignment data and they work great. There is a ton of room for improvement, but I'm just saying the whole civil engineering community is designing these things, and the autodesk crew got it wrong for pipes so a good chance to jump ahead of them.