Topography - Roads, Paths, Curbs etc...

[Grumple]

Hi all,

Just wondering the best way of going about creating things like roads, paths, and curbs for a topography...

In the past I've simply used 'Split Surface' and given the roads and paths a different material than the rest of the topo - I can't help thinking there is a more effective method. How are the road lane dashes added etc?

Also, is there a way of creating a 'Curb' family? So you could simply attach a curb to the edge of a pavement, or even draw one along the edge...


Thanks for any tips and ideas in advance : )

[Mike Sealander]

I think it best to consider Revit's site features "elementary", or SD-level.

[Grumple]

Ouch...

So no real way of creating proper roads with curbs etc?


I'm trying to figure out what to do with linked houses on an uneven topography... Could normally use a pad to sit the building into the topo - but when the building is linked, you can't give it a pad in the topo...

Can you use voids? : |

Cheers!

[patricks]

Sure you can use pads, but in your site file with the topo, of course.

I typically draw roads, parking lots, grass areas, etc. as floor objects for site plan purposes. This allows me to quickly create curbs as floor-hosted slab edge sweeps.

For 3D renderings, if the site is relatively flat, I'll just use those floors for the rendering. If it's not flat, then I'll try my best to grade the site correctly, using spot point very close together at a 6" height difference where the curbs drop down. Then I'll use the subregion tool, tracing over my floor elements, to create the roads, curbs, etc. in the topography. Subregions will keep the topography remaining all as one element, but will let you assign different materials to the different areas for rendering purposes. Then in the 3D view I turn off floors so that only the topography areas are visible around the building.

[Grumple]

Hi Patricks,

Thanks for that... I'll look into it tomorrow!

I'm bound to get stuck and ask more questions so keep an eye out :)

[Grumple]

I typically draw roads, parking lots, grass areas, etc. as floor objects for site plan purposes. This allows me to quickly create curbs as floor-hosted slab edge sweeps.

Do you mean literally using the 'Floor' command, or creating an in place family and making the category 'Floor' ?



If it's not flat, then I'll try my best to grade the site correctly, using spot point very close together at a 6" height difference where the curbs drop down. Then I'll use the subregion tool, tracing over my floor elements, to create the roads, curbs, etc. in the topography.

How can you make the spot points accurately run along a line?! Whenever I add a point or 2, the topo just goes kinda mad and gives me any random zig-zags it feels like... So you somehow literally model the topo including roads, curbs, paths - using spot points?!

It would be so much more helpful if you could add your own contour lines... : |

[Grumple]

Can you send me an example of your topo's?

Using floors is a great idea! But I still can't see how you do your 'non flat' roads etc... : |

[Andre Baros]

One helpful trick which has come up here before is to draft your sitework first in your siteplan, then use that as a guide when you modify your topo. There are two advantages.
1. You can get things to look correct, including hatches and linetypes.
2. If you create your topo by picking and locking to your drafted lines than all you need to update is your drafting lines, you don't have to edit the sketch every time you're changing your topo.

(this mostly applies to sub regions and split regions, not actual topo points)

[patricks]

Do you mean literally using the 'Floor' command, or creating an in place family and making the category 'Floor' ?



How can you make the spot points accurately run along a line?! Whenever I add a point or 2, the topo just goes kinda mad and gives me any random zig-zags it feels like... So you somehow literally model the topo including roads, curbs, paths - using spot points?!

It would be so much more helpful if you could add your own contour lines... : |

I don't usually slope the floors of the site elements, unless it's something obvious like a ramp sloping in one direction. The floors are really only for the site plan drawings, to show the lines and edges representing edges of walks, paving, curbs, etc.

But for rendering purposes, where I actually need to see those walks, curbs, paving, etc. I turn the floors off and use subregions on the topo, to create the different areas with different rendering materials.

As for the contour lines, realize that the earth's surface doesn't actually have contour lines on it. Every point has an elevation above sea level associated with it. When an engineer takes a survey of an area, he/she is only measuring the elevation at various points. The contour lines are just the engineer's "interpretation" of what the lines would probably look like, and in the case of a computer program generating the contour lines, this comes from interpolation between the points.

So if you have a 2.5 spot point, and a 3.5 spot point some distance away, the program interpolates and knows that 3.0 is halfway in between. Revit uses "triangulation" between points to establish the surface, which is why the contour lines often do zig-zaggy weird things. This can usually be remedied by adding more points, either points of the actual contour line values themselves, or points slightly above or below the contour line, to help "force" the line to go where you want it.

Yes it can be frustrating, but the more you understand how it works, the easier it gets to manipulate the surface. I usually place spot points at the corners and along the sides of buildings, at corners and along arc points of sidewalks, paving, etc. following rules for maximum and minimum slopes. For example the area around a door must have a max slope of 1:50 for ADA purposes. So I place points equal to the building finished floor around a door, and then come 5 feet out and place more points that are 0.1' below finished floor. 1:50 = .02 x 5 feet = 0.1 feet rise/fall.

For curbs, I will place a number of points along the bottom edge of the curb corresponding to how my parking lot/street is sloping. Then I will offset all those points by about 1 inch in plan, and change the new points to be 6" higher. Then I will make a subregion along the curb containing those low and high points, and change it to a concrete material.

Hope this helps some.

[Grumple]

Sounds like a good plan, thanks Andre!

Now about these roads...

Is it really a case of painstakingly picking hundreds of spot points THEN having to go back and basically do them all again (just 10cm diff elevation) but roughly free handing them as closely as possible inside the origionals in order to 'mimic' a curb... : |

Why can't they simply make a line based family that is set to follow topo elevation???
Can you make your own???

I'm sure I remember seeing a tutorial somewhere of a fence being created which can then be told to 'sit' ontop of the topography...

[Grumple]

Thanks patricks, that makes more sense now...

Sounds like a fair bit of work though... I'll get practicing!

[Grumple]

ok...

This has literally taken me hours today : |

There must be a better way than manually entering every point to get a smooth outcome!

I started off tracing an underlying 'road' floor object, putting points at each midpoint and endpoint... I then manually 'offset' each of these along a 'curb' floor object and gave them a 100mm lower elevation.

From then I have had to keep adding point after point between the origional points in order to break down the 'zig zags' and get a smooth looking road...

For some bizarre reason however, my road is bumpy!!

Take a look : |

Whats the dealio?!

[Andre Baros]

I didn't take a look at your file, but you may find it easier to edit the points in section. If you draw a section cut in the right place and limit your view depth, you can edit a row at a time in section and get really clean results. Also, to help this, I try to place all of my topo points in-line with each other.

[Grumple]

Thanks Andre, that sounds a good plan... But how would that work for a curved road?

I've attached a couple of pics to show my bumpy road situation.

1st shows the 3D view

2nd shows the points that are placed along the correct road boundary (traced), and the actual line that the topo is making...

Any ideas? : |

[patricks]

Yep, it takes a long time. Just yesterday I pretty much spent the ENTIRE day getting an existing toposurface to match the survey, and there aren't even any site improvements on it yet! I imported a large CAD survey, and imported the elevation data from the survey's contour lines, which gave me thousands of points. But I still had to go through and add lots more points to get the topo lines to behave and follow the survey's lines in all places.

I actually was trying to get the topo to follow an existing curb along the edge of the parking lot. But finally I just gave up on that and cut the toposurface back to the back of the curb, since all of our improvements will be back behind the existing curb anyway.

On trick you could possibly try is to grade the site smoothly as if there were no roads, then split the surface where you have curbs, and actually drop that piece of topo down 6" in a section view.

[Grumple]

Yep, it takes a long time. Just yesterday I pretty much spent the ENTIRE day getting an existing toposurface to match the survey, and there aren't even any site improvements on it yet! I imported a large CAD survey, and imported the elevation data from the survey's contour lines, which gave me thousands of points. But I still had to go through and add lots more points to get the topo lines to behave and follow the survey's lines in all places.

Mission : |

Why can't they just make a decent set of tools?! Seems like such a basic addition... 'Road - Select Topography - Draw Path - Finish'...




On trick you could possibly try is to grade the site smoothly as if there were no roads, then split the surface where you have curbs, and actually drop that piece of topo down 6" in a section view.

This actually works brilliantly! The only issue is the gap left by the different topo heights... Easy way of filling it in?

[patricks]

Mission : |

Why can't they just make a decent set of tools?! Seems like such a basic addition... 'Road - Select Topography - Draw Path - Finish'...

Apparently it's a difficult task to get solid geometry, with a thickness, to follow would would be a very compound and complex path. You draw the path in plan, but then the program would have to make that solid geometry blend and twist and turn to follow any irregularities in the surface. Remember that toposurfaces in Revit are just that, surfaces, with no actual depth or thickness. The poche you see in section views is just a "fill" that it places beneath the surface in any view that cuts it perpendicularly.



This actually works brilliantly! The only issue is the gap left by the different topo heights... Easy way of filling it in?

Yeah I forgot about that. It still works great for getting the topo lines to offset correctly in plan, since if a curb is 6" tall, the topo lines on either side of the curb's vertical surface will come in halfway in between one another.

[david.metcalf]

If you have Revit Structure you can use beam tool with curb profile applied to the path. By setting elevations at start end points of the path.

[Grumple]

I still think it'd be possible! I'm sure Civil 3D must have an idea of how to do it...

I guess after splitting and dropping the road section, there is no way of 'joining' or 'attaching' the 2 topographies together??? Just to fill the gap...


The beam curbs look great! I guess Revit Arch can't do that? : |

[Kirk Bricker]

You can create a curb that slopes with points. Create your parking lot with floors and use the points to get your slope correct at different spots. Edit your PL and copy to clipboard your sketch lines of your PL and use those to create a curb. Paste from clipboard those sketch lines into a new floor sketch mode (paste align to current view) offset your sketch lines for the floor/curb 6", make sure your curb/floor is 6" in depth in the type parameter of structure.

This parking island is currently 6' from FFE of the building.

Do the same exercise with the grass/floor.

Kirk

[david.metcalf]

I still think it'd be possible! I'm sure Civil 3D must have an idea of how to do it...

I guess after splitting and dropping the road section, there is no way of 'joining' or 'attaching' the 2 topographies together??? Just to fill the gap...


The beam curbs look great! I guess Revit Arch can't do that? : |

Sorry no it is a Revit Structure feature. I really think with some API or more programming a Civil toolset can be created. The topo tools are wonky and I cannot seem to get the contours the way I need them to be.

[Rick Houle]

Another thing that might help in conjunction with the Split Surface approach, is to "merge" the surfaces back together...

Think about it, First, you split your surface and you get a complete set of boundary points on the resulting new surface.. then you split that surface again with a slight offset, and now you have another set of boundary points... (keep in mind, you can turn off interior points to help with selection)

Now, change your elevation of topo, and change the spot elevations of your boundary points to create a seam with the original topo.... NOW, MERGE these pieces back together...

It sure helps me, when the alternative is entering a billion points along a seam...

SPLIT, MERGE, SPLIT, MERGE...

[cganiere]

I make roads, parking lots, grass & sidewalks the same way. Use floors.


Sure you can use pads, but in your site file with the topo, of course.

I typically draw roads, parking lots, grass areas, etc. as floor objects for site plan purposes. This allows me to quickly create curbs as floor-hosted slab edge sweeps.

For 3D renderings, if the site is relatively flat, I'll just use those floors for the rendering. If it's not flat, then I'll try my best to grade the site correctly, using spot point very close together at a 6" height difference where the curbs drop down. Then I'll use the subregion tool, tracing over my floor elements, to create the roads, curbs, etc. in the topography. Subregions will keep the topography remaining all as one element, but will let you assign different materials to the different areas for rendering purposes. Then in the 3D view I turn off floors so that only the topography areas are visible around the building.

[mark.98140]

my approach is much more straight forward... nonetheless a little cumbersome... i simply sketch the layout i want with drafting lines... then create a topo surface to as required... for the curbing it simply is a case of doing a swept blend kerb that follows the drafting lines... the ends of the curbs can be adjusted in height to match the topo... easily done.. then the next leg of the kerb can simply be adjusted in height by using the ends of the last bit of kerbing... quite simple... it allows for very accurate modelling of kerbs that follow the terrain. limitations are that swept blends cannot do more than one segment at a time... the manual height adjustment is fine... as you can view in 3d the changes and kerbs don't need to align to the millimeter , unlike some of the other optins for kerbing touted here...

hope this helps.... still wish we had a dedicated app for this!

[Norton_cad]

I saw this third party app that does the trick...
http://www.12d.com/model/

[franciscomarquezortiz]

Hi, i´m doing a projecto on roads excavtions a olot of land moving on revit. My doubt is, wnat happens when you want to make roads with PADS (to quantify the amount of land you are cutting a filling) and at the same time you want lo make some slopes at the side of the rode (i can draw them basically with a mass or slab but the thing is that i want to quantify how much land i´m i using)
I loaded an image of the idea i want acomplish, i was wondering maybe an in place model?

Hope any one has an idea

cheers!

Paco