Update the triangulation engine to 3D

[sboon]

I've seen several posts on this board related to vertical faces, overhangs etc.  The problem is that all of these are limited by the underlying problems with the Delaunay Triangulation algorithm, which Civil3d uses to build surfaces.

2d Delauney requires that there be a single direction for "down" so that the triangles can all be calculated in a common x,y plane.  It also requires that no two points can have a common x,y at different elevations.  When the software was originally created ten years ago 2d Delauney was probably the only viable option, but with improvements in computing power new possibilities are available.

3d Delauney algorithms can now be used to produce stuff like this.  I don't know for sure, but I suspect that the point cloud functions we've already seen in the 2016 ACad platform are already using something similar.  We need 3D surface triangulation in Civil3d in order to solve some of the other issues and requests here.

Steve
Please use the Accept as Solution or Kudo buttons when appropriate

[joantopo]

Spoiler

I add: focused to build tunnels!

I think that now is necessary 2 or 3 surfaces (top,bottom,...) to build a tunnel.

I would like some part of Civil 3D to define properly a tunnel.

[joantopo]

This is another example, using a shoulderExtendedAll Subassembly.

(yellow line is the corridor Surface section: code Datum)

You cannot calculate the area of the triangle within the corridor surface section.

I tried with my own subassembly (made in SAC) for ShoulderExtendedAll to have all the links with code Datum, but the results is the same.

[mikemcculley5692]

Agreed. As surveyor, there are times when an overhand or shelf needs to be made part of the surface.

[AllenJessup]

I fully agree. However we must realize that it will make creating existing surfaces more difficult. The concept of breaklines would have to become more complicated. They would have to contain information that prevents triangulation to lower points below an overhang. Possibly you might need break planes.

Allem

[francescamaier2656]

This is nice for quantities, but it doesn't reflect reality of how things are constructed. You can't build a vertical face with machine control. Ideally, we need to start developing out assemblies to reflect what is a machine control surface vs. what is backfill, since these are different construction activities and it's helpful to contractors to have those as separate quantities. Whether we as designers want to account for them separately or not is questionable, but we can define our Subgrade links according to however we want to calculate our quantities. Surface triangluation across vertical faces is annoying and leads to lots of problems, but ultimately, maybe we shouldn't be triangulating across a curb face? (Which we only do to display contours for drainage plans, right?)

Mesh objects do support vertical faces, so is there a need to create mesh surfaces from corridor models? Well, we get those out of the corridor solids. 

[efren7717]

Currently, Civil 3D does Triangulation fast and great, but the method is only reckoned from one horizontal plane. This is the reason why C3D cannot triangulate a perfectly vertical wall, or vertical cave-ins. If method is done with multi-planar, C3D could triangulate space-frame entities, vertical cave-ins and walls.Examples are sub-surface objects like kimberlite minerals, gold seams, etc. Vulcan software, is not limited to these methodologies. I come from the Mining industry and i understand that Civil 3D is meant for Roads and Land development only. But if Autodesk would extend C3D to the multi-plane triangulation, it would help many Mining consultants as the non-Autodesk products like MineSight, Vulcan and Surpac are ridiculously priced like a car.

[efren7717]

Autodesk can disrupt the Mining software cartel by making their own at reasonable price just like their current products by just even extending Civil 3D capabilities.

[peterfunkautodesk]

This is a duplicate of: http://forums.autodesk.com/t5/autocad-civil-3d-ideastation/update-the-triangulation-engine-to-3d/idi...

Regards,

Peter Funk
Sr Product Manager
Civil 3D
Autodesk, Inc.

[Cadguru42]

The TINN model used by Civil 3D for surfaces is outdated. There are many limitations to using triangles for terrain modeling such as inability to model tunnels, inability to have vertical faces, inability to model curves, extra polygons due to having triangles instead of quads, etc. Core AutoCAD has a surface object that is very flexible and can be exported to other software packages. Civil 3D needs to use this core AutoCAD feature to model terrain data for more accuracy and visual appeal. 

See http://forums.autodesk.com/t5/autocad-civil-3d-general/the-tinn-model-needs-to-be-replaced/m-p/65115... for more discussion.

[peterfunkautodesk]

Great idea, but it is going to need a deeper look by our development team to determine technical scoping, before potentially moving into our short term development backlog.

Regards,

Peter Funk

Sr. Product Manager

Autodesk, Inc.

[francescamaier2656]

TIN modeling may suck for visualization, but it's the foundation of Automated Machine Guidance data. There are other ways to make efficient visualization models, I wouldn't want to see Civil 3D lose rigor for AMG uses and volume computations. Tunnels, etc. are structures, so the way that data would be used, outside of visualization, is more appropriate for the corridor solids. Call me Eeyore, but this isn't a change I would make. I'd rather see data move seamlessly between applications (actual change propagation) and used in the right tool for the purpose.  

[peterfunkautodesk]

This one of the very serious considerations that we need to look at before we made a change to the system. Just as there are TIN and Grid surfaces, I would see a new mesh surface as a new surface type and not as a replacement of the current TIN surface.

Regards,

Peter Funk

Autodesk, Inc. 

[KirkWM]

That is a very good point Peter, I like that idea a lot to have a new mesh surface type. This would be a tipping point for C3D and reality capture as well! Would be a good consideration to have Infraworks push mesh surfaces of vertical faces to C3D and the ground terrain as either or.

[Cadguru42]

It's been a decade now. Nothing new from Autodesk on this requested feature. A decade is a very long time to implement or think about something like this. At this point, I don't think Autodesk cares. This will be ignored and nothing done while competitors will move on using more advanced technology.