Aligned Slabs and Spot Elevations (Not working)

[bphelps]

I have been piecing together through this forum and YouTube how to use the hardscape tool and aligned slab to create graded slabs using spot elevations. I need the precision of the spot elevations. I was excited to get it to work after hours of trial and error. Unfortunately, the tool is very inconsistent. It sometimes works and sometimes doesn't. You can see in the attached screenshot that the faces do not act the same in the three slabs. (I had to break it into three slabs just to get the two others to show up correctly, I'd prefer a single slab). Sometimes it seems it as a surface like the two on left and right and other times it doesn't and the surface stays at 0 elevations in places vs the spot elevation. I feel I have to use slabs for precision, assignment of cross section, and export to Revit for linking to team architectural model.

 

Is there something I am doing wrong or is there a bug that makes it inconsistent? I feel like I am going crazy. Very frustrated.  Is this a case of 462 ft being too far from the origin? Any insight is appreciated.

 

Brian

[Tom W.]

Can you post a file? Be interested to see what's going on. Thanks

[bphelps]

Sorry for late reply. Thank you for looking into it. I ended up getting the one I submitted to work with just trying over and over. There doesn't seem to be any rhyme or reason to it. It also often results in crashing VWX. Attached is another one that represents the same issue.

 

Brian

 

slab_error_example.vwx

Edited April 23, 2021 by bphelps

[Tom W.]

Thanks @bphelps can I ask what is it ultimately that you're trying to do? Because in the file, you've got a completely level slab at an elevation of 462.64'. You can achieve this by just having a Slab type Hardscape + entering the elevation in the O.I.P. You don't need to use surface modifiers to do this.

I am by no means an expert but the Hardscape tool is very flexible/powerful when it comes to adding slopes, manipulating the surface + editing its elevation + there are lots of different things you can do to achieve a range of different results. Can you explain what end result you're after as I suspect it's not just a level L-shaped slab at an elevation of 462.64'?

 

 

[bphelps]

I would like to have a slab that I can manipulate with spot elevations. My current workflow is to add spot elev that are all the same for the slab to ensure it is stable and creating the faces correctly. I only do this because the tool has been so unpredictable and unstable (saving every two minutes now). After I have confirmed it isn't going haywire, I then proceed to change the grades accordingly.

 

I cannot have flat slabs. They have to reflect real world grades. Ultimately, I am using them for sections, details, renderings, and linking to a team REVIT file (which is a whole other can of worms). This is my first foray into using the hardscape tool so I assumed I was doing something wrong in creating them.

 

Brian

 

[Tom W.]

Like I say there are lots of different ways of manipulating slabs + there may be a simpler way to achieve what you want depending on the circumstances. The easiest way to apply a slope to a hardscape is to have a standard slab type + apply a 'slope def' in the O.I.P.

 

If it is preferable to use surface modifiers, then have you tried grade objects instead?

 

You can use grades in conjunction with stakes: use stakes to set the elevations then draw grades between them then delete the stakes afterwards.

 

Hard to know without seeing a more specific example of what you're looking to achieve.

 

[bphelps]

Can I set one corner with stake and then slopes along edges to set other corners?  Will it display the slope?  I'll play around with the tool. BTW, it does seem that when I put stakes on corners that VWX sometimes doesn't read it. When I move it off corner outside slab it recently fixed it. Hoping that may solve it but it is hit or miss so far.  I do like the slope method if I can get it to work. It would save a lot of time. Thanks for sharing.

[bphelps]

Confirmed my questions above. Very helpful tool. Thanks again for explaining it.

[Tom W.]

No worries it's useful for me too!

 

To be honest, with so many other tools/options for manipulating hardscapes stakes would probably be fairly low down the list for me. I thought they were more for pulling the surface up or down at one particular point.

 

Profile lines are another option to look at. You can do a lot with them + easy to miss they're there as an option in the O.i.p.

 

Slab drainage is another way to add slopes 

 

Plus of course an aligned hardscape will slope automatically based on the adjacent objects 

Edited April 23, 2021 by Tom W.

[bphelps]

I assume site modifiers is only for the aligned slab (when using slabs). Your response made me think that wasn't the case. Also, can you adjust arrowhead size on slope? I have tried in classes. I couldn't directly do it when using tool because the arrow attributes were greyed out.

[Tom W.]

Do you mean Site Modifiers or Surface Modifiers? Standard Slab Hardscapes + Aligned Slab Hardscapes can both be used to modify a Site Model but that's a whole other discussion. Surface Modifiers yes can just be used on Aligned Hardscapes. Also Profile Lines.

But there are other types of Hardscape that you can use if you are wanted to apply slopes.

Like I said, standard Slab + use Slope Def parameter in O.I.P.

Or Slab Drainage type then you can use the Slab Drainage tool on it.

You can edit the size of the marker on the grade objects if you edit the surface modifiers, select a grade object, click on 'Settings...' in O.I.P. + click on 'Global Settings' tab. These settings will apply to all the grade objects in the file, existing + future.

[bphelps]

I think I mean site modifer (stake, grade tool). When I create a slab, I can add grading but it doesn't change the slab in three dimensions. I assume these two tools only work on an aligned slab vs other type slabs to create 3D topo with them.  In regard to settings, I missed the tab for global settings (Duh.) Thanks for explaining.

[Tom W.]

Stakes + Grades can be used to modify Site Models but I don't believe you're working with a Site Model? You can use Surface Modifiers + Profile Lines to modify the surface of an Aligned Slab type Hardscape, then if it is an 'Aligned Slab Modifier' type Hardscape you can in turn use the Hardscape to modify the terrain of a Site Model.

7 hours ago, bphelps said:

When I create a slab, I can add grading but it doesn't change the slab in three dimensions.

I'm not sure what you mean. Like I said before, the simplest way to slope a Hardscape is to have a standard Slab type + use the Slope Def in the O.I.P.

Edited April 24, 2021 by Tom W.

[bphelps]

Thanks. So far the sloping aligned slab is most reliable. I do still get crashing particularly if I save while modifying slopes. Also gettign so weird instances where the slope modifiers will change or not stick when I type them in. I have to do it twice to make it work sometimes. Not sure why. The workflow is creating accurate results when it works. I really appreciate you taking the time to explain this. I tried the slab tool and can't see how site modifiers are added. It appears it may be able to be sloped in one direction based on your example but for the slab nothing related to slope is showing in my OIP.