Cutting a toposurface with a solid

[daniel.loza]

Hi,

I placed some longitudinal custom shape (generic model form or void) in my toposurface and now I would like to find lines which represent intersection of this shape and toposurface (marked in the screen)end export thenm to .dwg. Thank you for any ideas.

[barthbradley]

I don't understand what you are trying to do?  Can you provide more information?  

...just a wild guess: you're not by chance trying to export to DWG for the purpose of importing it back into a Revit In-Place Massing environment so you can create a Mass Form from it?  

[Karol_Piroska]

I did exactly same few weeks ago. Refine contours, make sure the view is set to hidden line and then trace the intersection using model or detail lines. Not 100% accurate but it is the trick. 

[barthbradley]

---

@Karol_Piroska wrote:

I did exactly same few weeks ago. Refine contours, make sure the view is set to hidden line and then trace the intersection using model or detail lines. Not 100% accurate but it is the trick. 

---

What trick?  

[Karol_Piroska]

@barthbradley trying to find outline of intresection between toposurface and other sloped object and then export this outline as a dwg to be used lets say on CAD site drawings.

[barthbradley]

Yeah, still not following.  There are elements that can host to Toposurfaces.  Why not use one of those instead of "guesstimating".  

[Karol_Piroska]

@barthbradley 

https://forums.autodesk.com/t5/revit-structure-forum/sloped-topography-around-building-pad/m-p/85489...

[barthbradley]

Here @Karol_Piroska, let me return the favor:

http://aucache.autodesk.com/au2013/sessionsFiles/3340/913/handout_3340_AB3340_Make%20Hardscape%20Fol...

[ToanDN]

---

@daniel.loza wrote:

Hi,

I placed some longitudinal custom shape (generic model form or void) in my toposurface and now I would like to find lines which represent intersection of this shape and toposurface (marked in the screen)end export thenm to .dwg. Thank you for any ideas.

---

A topo surface is just a surface so it cannot be cut by another solid or void form.  There are several workaround:

1.  If you don't care about keeping the topo as a topo surface, meaning you don't need to grade regions, create subregions, add building pads, calculate cut/fill using the original topo tools, then you can convert it to a floor with modified points.

https://landarchbim.com/2015/10/21/make-hardscape-follow-topo/

2.  On the contrary, if you need to keep the topo as is, but show the trench, then split the topo surface around the trench area, edit the new surface and add points.

[cbcarch]

You could also try using a Building Pad.

[barthbradley]

Yep, pretty much what is described on page 7 and 8 of handout I posted a link to above.  

[daniel.loza]

yeah, that's exactly my goal (maybe I didn't describe it precisely enough)

[Karol_Piroska]

thanks  @barthbradley ,maybe I need my coffee but I don’t think you understood the issue. You want to find the location of a site cut line if you go from the edge of a building pad at constant slope - the top edge of excavation You can create a building pad but that will cut the topo vertically, not at a slope. The only way I managed was to create a sweep along the edge of my building pad. As you cannot cut topo with such element, I was only able to locate the intersection of these two elements using refined contour lines and then trace detail line that I could export into site drawings.

[daniel.loza]

I think the only solution for me is to set visibility settings properly (make cutting solid transparent) and trace intersection points with model lines (just as Karol described). Maybe I could also use building pad instead of model lines. 

[barthbradley]

@Karol_Piroska:  I can't visualize what you are describing.  Maybe you could draw me a picture? I do a lot of site work,  so maybe I can offer a more efficient workflow.   

[Karol_Piroska]

@barthbradley  maybe this will help:

[daniel.loza]

My analogical case:

[daniel.loza]

I'm just wondering also if it could be useful to convert a toposurface to a floor?

[barthbradley]

Gentlemen: I could pinpoint those hinge points, but math is involved. Trigonometry.  I would imagine we're constructing something, so there's got to be some real lengths and angles involved.  Or, are we just telling the backhoe driver to start digging anywhere, and to stop digging when the client runs out of money?   

FWIW: A Toposurface is just that -- A SURFACE. It has no depth or thickness.

In answer to your last question: you can use the approach I spoke about before to create a Mass Form from the Toposurface and then apply Roofs or Walls to Mass Faces.  There's a Dynamo Routine you can use to create a Floor (Variable or uniform thickness) from a Toposurface.   

[Karol_Piroska]

@barthbradley sorry, I think you have somehow completely missed the point of the excercise. It was to find out what would be the extent of excavation if you need to maintain a certain slope. As simple as that. And trigonometry as such does not apply here.

and I would dare to add - the toposurface is just a surface, it has no depth or thickness. But add another surface (graded region) at a different level at a different phase and you get the volume (unless it is too complex and split). Unfortunately with many limitations.