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Need Some Help in Grading

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Hi all I am struggling with the grading. Our site has lots of curved ramps and I don't know how to generate a smooth surface with accurate grading in VW. I attached a simplified file with my approaches of grading. Currently none of them works as expected, and I can't find an in-depth grading tutorial to tackle this. I would like to see if I can get any directions here.


I just don't know the correct work flow or grading tool to design a surface like this. The pad deals good with constant slopes, but when there is a slope change and two or more pads are needed, I can't seam those pads. The grading objects is good at creating precise spot elevations but it takes too much work to place enough control points in order to form a readable surface.  





can't seam those pads smoothly




the surface is messed up, it will take too much time to place enough control points


I attached the file below, if anyone is interested in helping to build it --- no matter the whole model or just a portion of it------ please post it back to me so I can study the methodology and tools. I feel I haven't changed to a corrected mind set in using VW grading functions. 


Thank you.

grading test v2020.vwx grading test v2021.vwx

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@DDD a few thoughts.

I attached a low res screenshot as well as a modified VW file, showing an option to achieve what I believe is your intent.??

Cutting the chase...

1) I added a texture bed on the surface so you could better see the areas you were wanting to slope etc.

2) My approach simply involved creating 3d polys for each of you sloped areas, and adjusting the height of each vertex on those 3d polys, to end up with the slope percentages you noted. ** Then going to 'recreate from source data' and pasting in place those 3d polys.

Then, when you exit that scenario and update the site model, it should look as you had intended.

Take a look at the file an peruse it a bit and you can better see what I trie to explain.

Hope this helps.



grading test MODIFIED v2020.vwx


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Pretty steep ramp from the low sloped pad, by the way :-)

Not sure how you intend to utilize all this.

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I forgot to mention one other thing.

You absolutely have to use 'mesh smoothing' when dealing with site models.

 IF not they will have a sharp, faceted look.

Note the settings in the screenshot below.  All your site models had no mesh smoothing.




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@Kevin K Hi Kevin, thank you so much for posting these. I have a couple questions:


1. The tutorial usually put site modifiers on proposed model to get a comparation between the proposed and existing. I noticed you place modifiers on the existing and regenerate the model, in this case I assume I can't generate a grading map with both proposed/existing contour shown. Do we have any other advantages by doing this?


2. I learned a similar grading methodology to your approach, which is to draw 3d polys/nurbs in the "SIte-DTM-Modifier" class and they will modify the proposed model accordingly. I copy your 3d polys and take a stab, it gives me a rougher version of your model. (top left is yours, bottom right is mine), I guess that could the reason you chose to regenerate the existing model instead.



3. In my case, there are much more points on the file. When our 3d polys encompass existing points, it will not flatten them like a pad. For instance I placed a couple interrupting points in the 3d poly area, and the model ends up with creating "hills". What s the common practice to deal with them? Just erase the existing points that are in our way?




I attached the updated file as well, thanks again.

grading test MODIFIED v2020 (1) v2021 v2020.vwx

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@DDD There are usually several ways to get things accomplished in VW, as I had pointed out. Do as you like.

As far as me putting things in existing versus site models...it was not high on my list.  I didn't want spend hours on this, if u get my drift. :-)

I was just showing how to get a nice smooth transition with the grade sloped you noted in your file.


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I did not look at the files yet. Will try soon. But, the terrain looks as though the DTM mesh is connecting directly to the ramp modifiers resulting in extra bumps and facets. A grade limits might help by allowing the ramps to sunk/rise into the DTM. Try surrounding the combined footprint of the ramps and platform with a poly ( trace or via the outer boundary tool), offset it a few mm, and convert the poly to a grade limits via Objects from Shapes. Update the site model. 

Just a thought


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