Bioretention Areas / Basins in a Site Model

[loretta.at.large]

Has anyone had any luck using site modifiers to model a bioretention area or basin in a site model?  I've been able to figure out some of the more advanced tools when it comes to grading a site model in Vectorworks, but creating a bowl shape has eluded me.  I think I could put together something decent if it was rectangular, but I'm attempting to model a curving, organic shape.  

 

What I'm trying to do here is model a bioretention area that the civil engineer designed and show that it would require a berm or wall to hold up one side.  I'd also like to show what kind of plants would go in here.

 

[Benson Shaw]

Do you know enough about the desired geometry to create a series of nested horizontal contours? They can be site mods or place them as source data, or place them in the SiteDTM class? Or, alternately place a bunch of 3d loci/stakes as source data?

 

If creating contours at the wall edge, make of each successive contour slightly inboard (eg .001in - vwx does not allow perfectly vertical site faces).  Screenshot looks like a grade limits is needed in order to fill in those pits. perhaps a big one all around the site is enough. Newer versions of vwx allow nested grade limits as long as they do not intersect. So a big one around the whole site and another surrounding the basin.

[Jeff Prince]

1 hour ago, loretta.at.large said:

Has anyone had any luck using site modifiers to model a bioretention area or basin in a site model?  I've been able to figure out some of the more advanced tools when it comes to grading a site model in Vectorworks, but creating a bowl shape has eluded me.  I think I could put together something decent if it was rectangular, but I'm attempting to model a curving, organic shape.  

 

What I'm trying to do here is model a bioretention area that the civil engineer designed and show that it would require a berm or wall to hold up one side.  I'd also like to show what kind of plants would go in here.

 

 

 

I can't really see what you are trying to do here, but I've created lots of organically shaped basins using contours and points.  They are like swimming pools, which there is a good modeling thread here on the forum.    In terms of site modeling, the bottom is the tricky part if you want that to be a curved surface.  What do you ultimately want to do, have an OK approximation using site modeling or a very accurate representation using modeling tools?  You can have both, but at a great expense.

 

 

 

 

 

35 minutes ago, Benson Shaw said:

vwx does not allow perfectly vertical site faces

It does in 2025 🙂

And if you are really tricky, you can get a small overhang it seems.

 

[VIRTUALENVIRONS]

On 3/21/2025 at 8:10 PM, Benson Shaw said:

Do you know enough about the desired geometry to create a series of nested horizontal contours?

Hi Benson,  do you use site modifiers to build site models or build everything in from scratch.  From your post it seems you might build everything in from the beginning. 

 

Probably can't pull as much information out as site modifiers, but certainly does offer a lot of power.

[Benson Shaw]

Hi, Paul!  In general, I prefer to create a Site Model from source data and apply site mods or other techniques to alter it.  If that's what your question means?

 

Trying to model a site via lofts or mesh etc can create a terrain of sorts, but if source data is available, a DTM is the easier choice for me.  As for adding the basin question in this thread, the posts above show that there are several approaches depending on operator skills and what is known about the envisioned shape. As @Jeff Prince shows, 3d modeling with conversion to DTM acceptable geometry can be a great advantage. 

 

Site Models are always approximations of the terrain, if for no other reason than the straight line connectors between source points. But usually, such deviation is acceptable.  Processes for simplifying the source data can make the virtual model less cumbersome at expense of increased deviation. But usually can be done within acceptable limits.  Blah blah blah, running on here.

 

-B

[VIRTUALENVIRONS]

Hey Benson,'

Yes normally I use source data, but either build in the extra data to create berms, swales, etc, or use the solids menus as opposed to site modifiers.

As I seldom ever have had a project that was stationary, always animated, this also gives more options in C4D.

 

But, I can see how for Architects especially,  the Hybrid Site modelling tools would be advantages.

 

The largest project I ever had was to recreated 5 square miles of WW1 Battle field and 120 miles of Allied and German trenching.  The only way to accomplish this was starring in VW's and finishing in C4D.  Neither program could accomplish this on their own.

 

But, like you so eloquently stated...blah, blah, blah

 

 

Edited March 24 by VIRTUALENVIRONS

[loretta.at.large]

On 3/21/2025 at 5:10 PM, Benson Shaw said:

Screenshot looks like a grade limits is needed in order to fill in those pits. 

 

@Benson Shaw - I did have grade limits, but the screenshot didn't show it well.  When I changed the grade limits to have straight edges (rather than curved), it starts to look much better.  For whatever reason it seems to not be an issue when other site modifier types are curved.

 

I'm just trying to demonstrate how the bioretention area would require a pretty substantial berm on one side and didn't want it to look faceted and ugly.   Anyway, problem solved!

 

 

 

 

[Benson Shaw]

@loretta.at.large Glad it resolved.  If you investigate more, eg to allow curves in the grade limits, one thing to look at is whether that GL crosses any other site mods. The plan view seems to show it inside the retaining wall & slab boundary opposite side from the pond. The notch in berm at end of slab could be corrected by adjusting the red line (landscape area?).  Anyway, looks pretty good now.

 

-B