Now that we started slicing and dicing new features in AutoCAD Civil 3D 2013 one feature caught my eye. In Surface Properties, Definition tab, there is a setting that does pretty similar task as “Use maximum triangle length”. This one is found right above it. It’s called “Maximum angle between adjacent TIN lines”. What does it do, you may ask? Well it is basically set to analyze and build surface more intelligently by eliminating TIN lines that exceed desired maximum angle. To see more, click on continue reading.
Off course, "Use maximum angle", must be set to “Yes” and then we can choose the maximum angle. Because I liked the image I found in help, I will save myself some time by just including it here. In this image you may see how it all looked, our criteria (130 degrees maximum angle) and final result.
One thing also worth mentioning is that this action only assesses triangle lines that create outer boundary, so no interior triangles will be modified. I guess the days of those large and strange triangle lines trying to span the surface area on the curve are over.
To demonstrate what I meant I used one of the tutorial files and created a simple corridor and corridor surface. Once it’s built this is what I was able to see. It did not look pretty.
Once I adjusted my TIN angles it looked much better.
There are two more details I wanted to share here, for all of you to be aware and not to remain surprised when doing this. If both “Use maximum triangle side length” and “Use maximum angle” are set to Yes, then the Use Maximum Angle operations are completed before the Use Maximum Triangle Side Length operations. One other thing is that surfaces created by older versions of Civil 3D may look differently if they are rebuilt with “Use Maximum Angle” turned On. The reason is simple, some triangles may get removed.