Terrain Issues

[ChiefJeet]

I have gone through several training videos and forum articles but still cannot seems to resolve the weird generation of terrain. More explained in the video. Can someone please help. Video added and will add the plan in the next post

[ChiefJeet]

Plan added

Terrain1 Elevation line.plan

[robdyck]

Try deleting the retaining walls...is that close enough to what you have in mind?

[robdyck]

If you'd like a continuous slope along the sides of the terrain, you'll need to provide Chief with more data. You can do this by using elevation points and using the transform/replicate tool to create a percentage graded slope. 

Alternatively, you can start placing an elevation point halfway along the property and keep repeating that process as necessary.

[ChiefJeet]

Thank you Robert.

This was just a simple start to demonstrate the issue. The building in your clip is not at 0 level but at the average automatic level. I would have gone onto drawing the retaining walls around and away from the building and generating pavement path and maybe steps up from the rear of the building. I did try your suggested method of generating manual elevation lines but then every time I place another flat region or a cut, the terrain regenerates in a weird fashion

[ChiefJeet]

41 minutes ago, robdyck said:

Alternatively, you can start placing an elevation point halfway along the property and keep repeating that process as necessary.

Tried gradual elevations lines and still generates unusual elevations. 

Has any of the experts from the forum done any videos on their You Tube channels?

 

Terrain1 Elevation line2.plan

[robdyck]

3 minutes ago, ChiefJeet said:

Tried gradual elevations lines and still generates unusual elevations.

Of course it does, you have elevation lines running through retaining walls. Instead of elevation lines, those should be points along the terrain perimeter.

[HumbleChief]

Not exactly sure what you are looking for but perhaps this will help.

 

 

 

TERRAIN PLAN.plan

[ChiefJeet]

Thank you Rob & Larry

I see that the conflicting data is causing all the issues

 

I broke and deleted all the elevation lines crossing the retaining wall as Rob suggested and it works fine.

It is bit time consuming as I could not trim the elevations lines using trim or subtract tools as they do not appear to work on elevation lines.

 

Thank you Larry for taking the time out to do the video.

I was trying to do exactly that but for some reason it got messed up. I will watch your video several times to see where I was going wrong.

This was a simple trial to experiments.

The aim is to insert a low level plot within imported terrain data.

 

I have the file with elevation points and not the elevation lines.

 

1. My initial thought is first to convert the plot to elevation break or create a retaining wall
2. Delete all the elevation points within the site boundary
3. Create elevation region and set the level to the required value

Thankyou guys. You have saved me days of work.

 

 

[ChiefJeet]

I have followed the above steps and create a level elevation area but don't know why I am till getting the weird transition lines.

Can someone please see what I am doing wrong in the attached video and plan file. Will send video in the next post

Terrain1 Elevation line4.plan

[ChiefJeet]

Video attached

 

[HumbleChief]

Hi Jeet. It's not clear what you are trying to accomplish? Is that a raised flat area within the datum field? Chief has a very complex method of calculating such things and the task you've presented is above my pay grade. Hopefully others can help.

[robdyck]

12 minutes ago, ChiefJeet said:

I have followed the above steps and create a level elevation area but don't know why I am till getting the weird transition lines.

Those aren't transition lines, they are terrain contours. It may help if you think of Chief modeling terrain like a wave. You have provide concise information for concise results. 

[robdyck]

In this area, you should keep in mind the 'wave' concept as Chief models the terrain around the elevation region. So, clearly Chief doesn't have enough information to produce your desired result. This means you should provide more elevation data around the perimeter of your elevation region.

[robdyck]

Let's take a look at these 2 elevation points. We need to add more data between these to 'iron out' the terrain contours in that area.

To do this, I will draw a cad line and use as a guide it to place additional elevation points at the half-way point and at half the elevation difference. I'll keep repeating that process until the terrain is smoothed out. All it took was the logical addition of 4 more elevation points to reasonably smooth the terrain. This isn't the only method, or necessarily how I would do it for my own project, but this is a simple concept to explain and understand.

 

[robdyck]

I'll perform a similar operation on the other side of the elevation region. Here, I've distributed the elevation points along a cad line at even intervals.

All that being said, I would agree with you; the Terrain Break is not modelling the way you would expect for a 100mm transition.

 

[ChiefJeet]

Thank you Rob & Larry

21 minutes ago, robdyck said:

the Terrain Break is not modelling the way you would expect for a 100mm transition

I understand that this is the best CA can do and have to iron out the bulges manually.

Without your tips, it would have been difficult to workout how to do it.

The attached video shows what my intension was.

I wish CA had more videos addressing these issues.

Thanks again

[Michael_Gia]

On 1/30/2023 at 6:56 AM, ChiefJeet said:

 

I have gone through several training videos and forum articles but still cannot seems to resolve the weird generation of terrain

 

Hi Jeet, I see that you are only looking for a simple slope to your terrain and then are wanting to put a sloped driveway.

 

I personally don’t mess around with the very hard and unpredictable terrain elevation data, lines and regions. 
 

Here’s what I do.

 

1 - Slope your terrain as you have done by raising the back end by 1m. 
 

2 - cut a hole in the terrain where you want the driveway to go. 
 

3 - you can make copy of the terrain hole and convert it to a slab or ramp, which will be your driveway. 
 

4 - make a copy of your driveway (or terrain hole) and convert it to a 3d moulding and adjust the moulding to be your retaining walls for the driveway.

 

If you work in this way then it’s real easy to make adjustments to your terrain or driveway or retaining walls/borders. 
 

[robdyck]

9 minutes ago, ChiefJeet said:

The attached video shows what my intension was.

This is very helpful and modifies how I might handle this. To start I'd create the terrain 'as-is' with out any modification. I would keep this as a separate Chief plan file. Using the terrain, I would create a symbol of the terrain (with or without a terrain hole for your property) and copy that symbol into my home plan. Then you could create the terrain for your property line without worrying about transitions and the ripple effect. This would allow you to easily modify the terrain within your property boundary to create the grading you'd like to achieve for your property while not affecting the adjacent lands. 

[ChiefJeet]

Thank you Michael for that tip.

The simple slope was just to get the practice. The real plot is featured in the video above with the imported data.

Practice and tips will help in the learning process.

 

[ChiefJeet]

5 minutes ago, robdyck said:

To start I'd create the terrain 'as-is' with out any modification. I would keep this as a separate Chief plan file. Using the terrain, I would create a symbol of the terrain (with or without a terrain hole for your property) and copy that symbol into my home plan.

To create a symbol, do you mean using "Cad detail from view" and copy and past the cad contour lines and convert them to elevation lines?

[robdyck]

No. Use the "Convert Selected to Symbol" tool

[Alaskan_Son]

4 hours ago, robdyck said:

Those aren't transition lines, they are terrain contours. It may help if you think of Chief modeling terrain like a wave. You have provide concise information for concise results. 

 

Good information.  I'd like to expand a bit upon it though.  The top one can actually be achieved in large part by simply setting Terrain Surface Smoothing to Linear:

 

Any other setting though and you are correct.  We get a wave behavior:

 

I think the thing people tend to expect less though is how the terrain is interpolated beyond the specified elevation data because we have to remember the interpolation and the resulting "wave" does have to continue:

 

And what is even more difficult to account for is what happens when additional elevation data is added that directly affects what happens between the previously specified points:

 

 

It should also be noted that the above examples are perfectly orthogonal projections.  This is all much further complicated by off angle elevation lines/elevation points (and the resulting 3D waves) as well as the fact that the interpolation can start to affect objects around corners (around the end of elevation lines and around the ends of terrain breaks). 

 

I think the bottom line is that we have to remember that interpolation is taking place and that any given piece of elevation data can have a far reaching effect.  Any modifications to elevation data at one location can have effects across the entire terrain.  To limit these effects you may want to place new elevation data at your desired extents to help "lock" those particular locations.

 

In the example given by the OP, one thing I would consider doing is generating a terrain based on the elevation points and then using the Contours tab to generate and label an adequate number of contours that I could then use to help add some of the aforementioned "locks".  I could either add additional points at various perimeter locations, or I could even create a CAD Detail From View, copy and paste the various contours, convert those to properly defined elevation lines, and then use those instead of or even in addition to any number of elevation points.