Terrain Elevation Issue


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I am modeling the house shown in the photograph below. 



The main floor of the house sits above the road about 12-15 feet.  The driveway is sloped upward a couple of feet from the road to the garage.  I want to put in the terrain, but I am having a few problems.  I have read the chapters on terrain and watched all the videos, but I can’t figure out how to create the sloped driveway 12 feet below the main terrain perimeter.   Another issue that is related is that when I add the road and open the Road Specification dialog box, I don’t see a way to change the elevation of the road.  This leads me to believe that the road has to be at the base terrain elevation (i.e., 0”).  Is the correct approach to set the overall terrain around the house at -15 feet and then “raise” the terrain for the side yards?


So, my main question is this:

What are the general steps to create the terrain around this house?


Thanks in advance for your help.


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Thanks for the response.  I have reviewed the Knowledge Base and have studied the walkout basement design.  The difference between what they are creating and my design is that they have a uniform slope from front to back.  The design I am trying to model has a level portion in front of most of the house, then a slope to the road, with a large "cutout" at road level for the driveway.  Then I have to add the retaining walls between the level portion and the driveway, not to mention that the driveway also slopes.  I am just stumped about how to get started.  I'll keep looking in the meantime...



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JoAnn, thanks for pointing me to the Knowledge Base article on Using Terrain Features and Regions.  I have reviewed that article before, but I thought I would take another look at it, because obviously I’m missing something important.  I tried to take my plan and apply the steps in the article, but right off the bat I could see differences in what they are trying to do and what I want.  I have so many questions, I don’t quite know where to start.  But let me just start by walking through what I did and the results I got from those steps.


My first objective was to show the hill in the front yard that extends down to the road (shown in Picture 1 below). 




The actual flat portion of the yard that can’t be seen from this view extends out about 10-15 feet from the porch step before dropping off very steeply to the road.  The slope that is seen in front of the house is probably a 60-degree drop from the flat portion to the road.  In my model, I already have the house and front porch/steps done.  These are shown in screenshots of the plan and 3D views (Picture 2). 


My next step was to create the terrain perimeter.  Here’s where I get a little stuck, because if I put the base terrain level just under the bottom step, I’m not sure how to lower the level of the road when I add it.  But I’ll cross that bridge later since no one has steered me otherwise.  I added the Terrain Perimeter and opened the Terrain Specification.  The Building Pad was set on Automatic, and it was at 20 1/8” (greyed out).  I unchecked the Automatic box and changed the Subfloor Height Above Terrain to 22” to fine tune the position relative to the bottom step.  My terrain is currently flat completely around the house.  A screenshot of the plan and 3D views is shown in Picture 3.



Next I wanted to create the flat area in front of the left part of the house where the driveway will go.  The driveway will be approximately 150” below the level of the flat terrain shown in Picture 2.  According to the article, proceeding from Step 5,

5.  When the Terrain Perimeter is the desired shape and size, select Terrain> Terrain Tools> Elevation Line  from the menu, then click and drag in the drawing area to create your first elevation line. 

Only the portion of an elevation line drawn within the Terrain

Perimeter will affect how your terrain is generated. 


6.  Once the elevation line is drawn, it can be moved and its length adjusted as needed by selecting and using the edit handles. 

7.  With the elevation line selected, click the Open Object  edit button to open the Elevation Line Specification dialog and specify the desired Elevation.

Following the direction of Step 5, I drew a series of horizontal lines in the plan view where the driveway will go (drawn in the X-direction).  This is shown in Picture 4.



I then marqueed across all the lines so I could change their elevation at the same time.  I set the elevation to -150” and clicked on OK.  The result is shown in Picture 5. 




The entire terrain was moved down to the -150” elevation.  I thought I was following the instructions in the article to the letter, but it certainly didn’t give me the result I wanted.  Again, according to the article,

·         Additional elevation lines can be added to control slope steepness and direction



The implication of the above diagram is that if you draw 5 lines and set them at -320”, this will cause a valley that will be 320” deep and the “sides” to this area will gradually slope to this elevation in the area of the five lines.  That is not what happened in my case. 


So, this is one of those cases where I must be missing something very basic – maybe the first few steps I took were wrong, causing the rest of the terrain model to do funny things.  I would very much appreciate if someone could tell me specifically what I am doing wrong. 




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Sometimes it's easier to show an example, rather than trying to explain.

So I did a mock-up of your plan, using some of the dimensions you supplied, and the rest are guesses.

Terrains can be tricky.  Tip: avoid using elevation points.

In this plan, I used only 2 elevation regions, and 1 elevation line.


I hope this helps...at least maybe it will get you started in the right direction.  :)








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Wow!! What a lot of work you did for me.  Thank you so much.  I have gone through the file quickly and I am wondering about the order of doing things.  Did you create the front slope to the road across the entire terrain first?  I was able to reproduce the front slope by drawing two elevation lines across the front of the terrain and setting one to -75" and the one closest to the road at -150".  Then I added an elevation region covering the rest of the property and setting that to -20".  That worked for the front slope!! 


Now I am wondering how you did the driveway.  I'm not able to create it using another elevation region extending from the road to the garage and setting that elevation to -150".  Can you briefly describe the steps you used to create the driveway?  I'm also intrigued with how the wall looks.  Is that a retaining wall?  How did you get the steps in it?


Thanks again for your help.  You have gone above and beyond on this one and I hate to keep asking you questions but I am not able to figure out the driveway, and the documentation doesn't seem to cover this situation (or maybe I'm a little dense). 



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I don't think it matters what order things are done in the terrain.
Open objects to see what they are.

The 2 walls lining the driveway show wall type as foundation walls, but they are retaining walls.

I don't understand why you set the remaining elevation region around the house at -20".   If you set the main terrain correctly, that region should be set at 0".  As I said, open the objects to see the information.

I deleted the 1st zip plan, and uploaded an updated plan.  If the plan you opened show a cross hatched pattern over the yard steps (1st floor level), then you have the updated plan.


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Did you use terrain retaining walls on both sides of the driveway?   

Is the lower elevation set at the street end of the driveway? 

If you open the driveway object, you will see that it is a terrain rectangular feature, and it will follow the slope.

You need to post the plan, to get more specific help.  
It would show what you have done "right" or "wrong".

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I am slowly but surely figuring some of this terrain stuff out.  I opened the plan you generated and opened up the various terrain objects to see what they were and what settings you used.  Since you said the order of adding objects didn’t matter, I started by adding two retaining walls on either side of the driveway.


Then I added a small Elevation Region and got the “terrain spikes” shown below. 

5ba932ab0b4fc_Picture8.thumb.jpg.93f0232672fd2b2b82b57d279a12043d.jpgTerrain Trial.plan

Finally, I added a Rectangular Feature like you did to cover the area of the driveway.  This didn’t remove the spikes as you can see. 


I thought I had duplicated everything you did but I got different results.  So obviously, I’ve done something wrong.  I’ve attached the simple file I created.  I’m hoping it was something simple that I neglected to do or a setting that isn’t right.  Thanks again for all your help.


Terrain Trial.plan

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Posting the trial plan, revealed the problem.
On the 0" elevation region,  pull the horizontal cutout area around the garage all the way to the back wall of the building.  This eliminates the spikes.  The driveway levels and  then slopes down to the street  

I see that you found the small elevation region that I placed in front of the garage door.  I had forgotten to highlight it with a hatch pattern.
I also see that you changed the subfloor height above terrain to 35" instead of the 22" you 1st mentioned?
If you add an elevation line set at -60" about midway between the 0" elevation and the -150' elevation, it will help to round out the harsh terrain drop.

I sure hope that you post a pic of the project when you get it correct!  :)
Here is an updated version of my plan.



TominOhio 2.zip

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Thanks for all your help.  I never would have figured out that I had to extend the 0" elevation cutout to eliminate the spikes.  I tried everything I could think of, but nothing worked.  I'm glad you solved that mystery for me.


I really like your updated version of your plan.  It looks great.  I'll continue to work on mine and will post a picture of the project when it's finished.  Thanks again!



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  • 2 months later...

Hi T,


Would you mind posting the final version of your project.

I have similar questions with the terrain and retaining walls as a new starter.


I have been looking at JoAnns replies but am curious how you got about. 

My terrain would have quite a few more different elevation levels.




Tom L

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