NURBs Surface as Site Modifier

[JamesRS]

Hi there,

 

New to this forum so apologies if this has been discussed previously. We have recently moved to VW and I am loving it! However I cannot seem to figure out if I can use a NURBs surface as a site modifier? If not, is there a workaround and if so, how do I do this!! We are trying to place some organic shapes into an existing site for pump track design.

 

Cheers,

James

[Katarina Ollikainen]

Hi @JamesRS, yes, you can use both NURBS and 3D polys as site modifiers - you must just put them in a specific class, Site-DTM-Modifier.

You can't create this class by yourself - Vectorworks will do that as soon as you use a site modifier in the file. 

The same rules apply to these modifiers as for 'normal' site modifiers (which contain 3D polys if you ungroup them) - you must have a grade limit around the area. Otherwise, you'll have unexpected results (see the image - the first one is with a grade limit, the second one without.

[zoomer]

While I can't imagine that complex NURBS surfaces could be a valid

source element for site modifiers ....

 

I think it would be cool.

 

While typical modifiers usually produce an artificially straight slope with

hard edges at bottom and top, with NURBS surfaces you could control

a more natural look similar to your example.

(E.g. erosion would "fillet" the top edge and offload it at the bottom which

will flatten the slope at bottom)

I usually try to manually edit my proposed DTM vertices to smooth things

out.

 

Of course there are also nice landscape examples of geometrical hard edged

slope formations done by intention.

But usually we are used to natural forming and nature is more grungy

than simplified geometry.

[JamesRS]

25 minutes ago, Katarina Ollikainen said:

Hi @JamesRS, yes, you can use both NURBS and 3D polys as site modifiers - you must just put them in a specific class, Site-DTM-Modifier.

You can't create this class by yourself - Vectorworks will do that as soon as you use a site modifier in the file. 

The same rules apply to these modifiers as for 'normal' site modifiers (which contain 3D polys if you ungroup them) - you must have a grade limit around the area. Otherwise, you'll have unexpected results (see the image - the first one is with a grade limit, the second one without.

Thank you so much for your responses, it works well with the Site-DTM-Modifier class. Once I have done this can I control the grade at which my site modifiers "connect" to the existing topography of the site model. I.e. could you specify a downward grade of 1:4 (rise:run) for the surface in your screenshot to run down and meet the site model? I can see you can do that with some site modifiers like a pad but cannot quite work it out for my nurbs surface modifiers.

 

Many thanks.

[Katarina Ollikainen]

@JamesRS, You can specify a slope on the modifier itself, but you can't control the slope of the edge (right now). There are workarounds you can use, though, but they require a bit of manual labour:

After creating your modifier, ensure you're viewing the existing site model (not the proposed), use the grade tool and place grades perpendicular to the edge of the modifier, and with the slope you want to give your modifier edge. Make them so long that the end disappears into the site model surface. Use them only for visibility, not to change the site model. In a 3D view, place a 3D loci where the grade object disappears into the site model. Go to top plan view.

This will give you a 'dotted line of where a specific grade edge would coincide with the existing surface. Now, draw a grade limit, following these markers. A grade limit will always apply to the existing site model, and hence, you'll create a boundary for the slope from the modifier to the existing site model surface.

Return your view to proposed, and you'll have your edge with a specified slope. 

There are other ways to achieve controlled sloped sides as well, but I've found this to be the most reliable so far, especially if the site model surface is undulating.

 

If you have a flat surface modifier to start with, you can also create a solid with the same shape and taper the sides, then place it aligned with the site modifier and trace around it with a grade limit (last image).

 

If you want to apply something like this to an already modified surface, use a 3D poly in the DTM-Modifier class instead of a grade limit and send it to the surface - it will do the same job as the grade limit, but can be sent to the proposed surface.

 

 

[Jeff Prince]

On 11/30/2023 at 1:39 PM, JamesRS said:

Thank you so much for your responses, it works well with the Site-DTM-Modifier class. Once I have done this can I control the grade at which my site modifiers "connect" to the existing topography of the site model. I.e. could you specify a downward grade of 1:4 (rise:run) for the surface in your screenshot to run down and meet the site model? I can see you can do that with some site modifiers like a pad but cannot quite work it out for my nurbs surface modifiers.

 

Many thanks.

 

The VWX Site Model tool is probably the wrong tool for this kind of job.

I model pump tracks with 3D polys of the tread elevation typically since that's how we design the profile of berms and jumps for such things.

You can use 3D polys as data for a site model, but the results are typically unreliable in terms of grading data and visually lacking the character needed for rendering....

 

site model contours have a few issues

 

Bottom model is 3D Polys, top model is same polys used as site model data.

 

 

 

[pitter]

On 2/15/2024 at 1:09 AM, Jeff Prince said:

I model pump tracks with 3D polys of the tread elevation typically since that's how we design the profile of berms and jumps for such things

Hi  @Jeff Prince

Could you upload a sample file here? We currently also have to model a pump track, but don't know how to do it best.
Thanks in advance.

[Tom W.]

Just wondering if a pump track could be modelled as a Path configuration Hardscape...? Not really used it much since it was introduced but you could add lots of Transverse Profiles to form the ups + downs then angle them on the turns: not sure if that would be too much work + not be smooth enough or whether it'd actually be ideal in terms of the degree of control + edit-ability it gives you...

[VIRTUALENVIRONS]

I don't do much with Terrain models anymore, but I understand them.  Unless there was something unusual about the data, I would build the track into the survey data at the start and not as a modifier.

1-Convert my Survey data from contour to 3D loci.

2-Build the tract separately

3-Go to low poly conversion mode and convert the track to 3D Polygons.

4-Select the converted file and extract points using the Extract Tool. (use select all entities)

5-Place this points where you want them removing points that are above grade

6-Create Site model.  

 

See below.  NOTE: only had a few. minutes this morning and did not use complex tract for this purpose.

 

 

[Jeff Prince]

2 hours ago, pitter said:

Hi  @Jeff Prince

Could you upload a sample file here? We currently also have to model a pump track, but don't know how to do it best.
Thanks in advance.

There was some discussion and examples a while back on this topic here:

 

 

[VIRTUALENVIRONS]

I had some time this afternoon.  I am not a Landscape Architect, but use the site model where I need it.  If I needed a pump track in my site model I would build it in from the beginning.

 

I realize that this may or may not work for everyone, but maybe it will help someone.

 

Below is a short Video showing the steps.