Lab Prep

First lets confirm we have checked out licences to 3D Analyst in ArcGIS Pro.

In Settings > Licensing, if your Extensions are set to Licenced No, we will need to licence them before proceding, otherwise you can skip to the inroduction.

Click on Configure Licensing Options

Select all checkboxes then press OK

You should now be ready to go!

1. Introduction

“To lose patience is to lose the battle.” – Mahatma Gandhi

Today we will be working with 3D data, and a couple of notes before we begin, it is not ideal to be doing 3D work on shared computers as many opterations will consum all available resources until complete. And it is not ideal to be doing 3D work over remote desktop, as movements can feel slow and chopy even while at the computer, the internet amplifies this feeling. Todays lab is deliberatly relativly short, and the key to sucess will be to stay calm.

This is simply the reality of working with large files in real-time 3D (a note from Matt: I have done this type of work once where all the motions felt smooth and that was on a $20,000 computer to provide some context).


2. Contour Lines

In lab 4 we used contor lines on our map of smithers, and today we will be taking it a step further and instead of just placing these lines on the map as is common on topographic maps we will be using the contor lines to make a digital elevation model, and add some shadow effects.

Open your color map of smithers from Lab 4 (if you for some reason no longer have your lab 4, you can copy this directory L:\GEOG205\lab06\smithers into your K drive and open this project in ArcGIS Pro).

Creating a DEM

Open the Tools pane from the Analysis tab

Search for the “Topo to Raster” tool

Set

Feature Layer to contor
Field to ELEVATION
Type to Contour

Output cell size to 30

For output extent choose contor from the drop down (Note the text will revert to As Specified below, but the numbers below will have updated).

Leave all other settings on default and press run (This will take 1-2 minutes to complete)

Next in your drawing order turn off contor, and vegitation.

Select the new DEM layer you created, and set the symbology to stretch

You should have something as below

As you can see in this digital elevation model the pixels of the image represent the elevation, white pixeles are the highest values and therefor the highest elevation.

It is likely more common to receive elevation as a DEM than contours, not that if you want to make a topographical map you could produce the contours from the DEM with the “Contor” tool, we will not be doing this in today’s lab, but the process is very similar as above, simply pick the input DEM, give it an output name, and set the interval.

Discussion Question: What was the contor interval for the smiters dataset?


3. Hillshade

Digital elevation models are not the most visually appealing on their own, so to add some visual style we will create a hillshade.

Create hillshade

Open Raster Functions

At the very bottom you will find Surface > Hillshade

We will start by making a Traditional Hillshade
Select your DEM created in previous step from the drop down, and leave type as traditional.
Azimuth is the compass direction the ‘sun’ will be coming from to cast shadows 315 degress represents North West, but if you want your shadows on the other side of the mountain this can be changed.

Altitude is how high on the horizon the ‘sun’ is in degress with 0 being at the horizon (very strong shadows cast), and 90 being directly above (very few shadows, with no decernable direction).

This should produce results as below

If you want to avoid shadows all being on one side of the terrain, instead of setting the Altitude to 90 degrees, use multidirectional as opposed to traditional hillshade.

Finally

Turn off the DEM, and all but one of the hillshade layers you just made

Ensure World Topographic Map, and World Hillshade are turned off.

Move the hillshade layer you still have turned on to the very top of the Drawing Order.

In appearance set Transparencey: 60%, and Layer Blend: Luminosity

Your map should now have a nice 2.5D effect


4. Creating 3D Scenes (This is where the computer will slow down)

Open ArcGIS Pro Again and Create a new Local Scene from the templates and name your project lab06-3d

Now lets examine the drawing order for the Scene, in the map we had only a single catagory now we have three catagories.

3D Layers, this is for layers that have elevation information attached (ie contours) we will not be using any of these right now, these layers will be displayed at an altitude based on the contained data.

2D Layers, these are the layers you have been working with to date, and function exactly the same as they did in the map, except they will be draped over an Elevation Surface

Elevation Surfaces, this is the 3D data that 2D layers will be displayed against.

*Note on 3D Layers, the elevation can either be above ground level or absolute, when elevation is absolute errors in alignment between 3D Laers and the Elevation Surface could cause the layers to end up below the ground and thus not visible.

We will start by turning off all 3 of the default layers and giving us a clean canvas to work with.

Add a folder connection for the Lab 6 data L:\GEOG205\lab06

Right Click on Ground in the drawing order and Select Add Elevation Source, in the lab06 folder you will find an alps subfolder and a layer alps_dem.tif select this layer. Note you will not yet see a change take place.

Next add the apls_ortho.tif file just as you would to any other map from the catalog.

3D Navigation

Using the 3D interface can be a little unintuitive at first, below are the mouse movements to control the map. Spend a couple of mintues exploring the alps and getting a feel for how to move the map around all of its axes.

Pan map – Left Click and drag

Zoom Map – Scroll Wheel or Right Click and Drag

3D Tilt – Middle Click and drag or [Shift] + Right Click and drag

Hypsometric tints

Note that the process for creating hypsometric tints is identical on the regular 2D Maps.

Start by adding alps_dem.tif as a visible layer

Next go into Imagery then Raster Functions

Search for “Shaded Relief”

Set the Raster as alps_dem.tif, and pick a suitable Color Ramp: Note that Left to Right is low elevation to high elevtion.

Do this process a couple more times with differnt colour ramps to see how the appearance changes. Not that different terrains will look better with different color ramps.

As a general note, ramps starting with a blue are generally only appropriate when the scene contains water, in which case it should be adjusted so the blue represents the waterline. As an example of this take a look at the default colour ramp below, aside from the red being overpowering, notice how if you did not know there was a settlement in the valley this image makes it appear as though there is a river, and the tan looks like a beachline. This is not helpful for your end users!

Note if you terrain looks to flat (or not flat enough) you can change the vertical exageration. Select Ground in the drawig order.

Then go into the Aperance tab and you will be able to set the Vertical Exaggeration.

Note that when you change the exageration it will change the height of your map, and may take it out of your current view point, the easiest way to find your map again is to right click on one of the layers you added and zoom to layer.


5. Fly through

At this point we have a 3D scene that we can look around set to the perfect angle and send someone else a photo of, however in some cases, it may be more beneficial to send someone a video of this scene. We will accomplish this through a process known as keyframe animation.

Go to View and Add Animation

A new toolbar will have appeared below your scene with only a single button. First, adjust the view to how you would like your movie to start, then press “Create First Keyframe” and your Animation Timeline will appear!

Next move your view to a different angle you would like to show off then press the Green +, and you will notice a 2nd frame.

If you press the Play button you will see the scene calculates all of the inbetween frames to make an animation (though it will still be very choppy at this point!).

You can continue adding as many frames as you like to create a tour of the scene.

When the animation works the way you want it to, it can be exported as a movie, this goes through a process called rendering. We will not be exporting the movie as part of lab as this process takes several minutes to an hour depending on the length of your animiation. The time this process takes to complete is the reason why the preview was choppy, the computer is unable to process frames of the movie as fast as it would need to, inorder to create smooth motion. However the exported movies would play back smoothly and could be shared with clients or on social media.


6. Assignment 5 (5%) due before next weeks lab

For this weeks assignment we will be building a simple map of Prince George, all of the layers you need are in L:\GEOG205\lab06\Assignment.

Part 1

1.) Make a simple map, using the Road Centerline, Trails, Buildig Outlines and Hydrology, (you will also use Contours to build a DEM)

2.) Convert the Contor Layer into a DEM – Use 20m cell size (This will take about 4 minutes to process, a good time to stretch, or grab a coffee!)

3.) Create Hillshade From the DEM

4.) Use the hillshade to add the visual relief (Note: do not use the “shaded relief tool” just the hillshade layer) as we did on the Smithers map at the beginning of lab.

Part 2

1.) Add a new local scene to your project Insert > New Map > New Local Scene

2) Replace the elevation surface with the DEM you created for the first map. (You will find it inside of your projects default database in the catalog.

3) Add the layers for Roads, Trails, and Bulding footprints.

4) Find an interesting viewpoint for your 3D map, note that you will most likely need to increase the vertical exaggeration as Prince George is relatively flat. Also, consider changing the basemap to get a more pleasing appearance.

5) Create a new layout, scenes can be added to layouts through the same process that you added the map frame in part one of the assignments (and every other assignment so far).

6) Add your name and title, for the 3D scene the legend is optional. Scale Bars and North Arrows should NOT be used as they will be incorrect due to perspective.

Categories: GEOG 205Labs