topic Re: 3D Scene - Drape image over 3D layers? in ArcGIS Pro Questions

3D Scene - Drape image over 3D layers?

Daniel_Hardwick — Wed, 23 Jun 2021 10:33:40 GMT

Hi,

I am creating a 3D scene and wondered if it is possible to drape an image over a 3D layer, such as Mastermap.

I am relatively new to 3D, but I have a scene setup which is using Mastermap data (joined with Mastermap heights csv data), so the Town Centre has 3D buildings. I can drape over a basemap or aerial imagery onto the elevation surfaces, but obviously the buildings extrude above this. Is there a way that I can make the aerial imagery drape over the 3D mastermap polygons?

I have achieved something similar using a Digital Surface Model, as I can use this as an elevation surface, and then the aerial imagery drapes over this. It doesn't drape over the DSM that well though, which was expected, and I feel draping over the Mastermap polygons would look much better with the heights being generalised (obviously far from perfect though).

I also wanted to be able to do this to make a new building in the Town Centre look as realistic as possible. I was hoping I could extract out just that particular building and then add in some images for each angle. Not sure if it is possible though or if there is any workarounds?

Re: 3D Scene - Drape image over 3D layers?

JayantaPoddar — Wed, 23 Jun 2021 11:23:26 GMT

Is the 3D building Feature Class in multipatch geometry?

Then, you can

1. Convert Multipatch to Raster , you may opt to keep the cell size same as the DEM Raster.

2. Add the above Raster to the DEM using Raster Calculator. Expression: "MODEL_Z_RASTER" + "DEM_RASTER"

3. Try draping the satellite/aerial image on top of the new DSM Raster.

Re: 3D Scene - Drape image over 3D layers?

Daniel_Hardwick — Wed, 23 Jun 2021 11:34:15 GMT

Thanks Jayanta,

I don't think the layer is in multipatch geomtery. The data was created from standard mastermap polygons (geodatabase), and then joined with MM heights. So the data is a standard polygon which I then brought into a scene and used the height field in the Extrusion options to make it 3D.

Do I need to try convert the polygons into multipatch geometry? Then follow the steps you mention?

Re: 3D Scene - Drape image over 3D layers?

JayantaPoddar — Wed, 23 Jun 2021 12:44:27 GMT

No. Just do a Polygon to Raster as first step, in the workflow I shared. Keep the Z Field as the Value Field of Raster. Keep Cell size same as DEM Raster

Re: 3D Scene - Drape image over 3D layers?

Daniel_Hardwick — Wed, 23 Jun 2021 13:54:42 GMT

Thanks, I will try that later this afternoon.

Just want to check something about the DEM you mention, is this the built in WorldElevation3D/Terrain3D elevation surface? Or do you mean my own DEM? I know I mentioned in my initial post that I used a DSM to drape the aerials, so just checking.

Re: 3D Scene - Drape image over 3D layers?

JayantaPoddar — Wed, 23 Jun 2021 14:10:04 GMT

I meant your own DEM/DSM (Raster Dataset). What is the source of your DSM? If it is older than the date, the building was built, the elevation value of that area could be same as the ground elevation.

Re: 3D Scene - Drape image over 3D layers?

Daniel_Hardwick — Wed, 23 Jun 2021 14:18:08 GMT

I thought that must be what you meant, but I am not sure this would work for existing buildings.

The DSM I am using is from Defra (50cm), and I was testing this drape on an existing building. So the building already will exist in the DSM, so adding the new raster to this DSM is probably not going to work as planned. This could be a good option for adding a new building though.

For draping over existing buildings, I could possibly create a DEM, and add the relevant Mastermap polygons into the DEM (using the polygon to raster and then raster calculator). I think that should work, as the DEM would not include any buildings? Quite long winded but it might be the only way...

Re: 3D Scene - Drape image over 3D layers?

Daniel_Hardwick — Wed, 23 Jun 2021 15:46:31 GMT

Just to add, I decided to try making the raster from a single polygon (stadium), and the raster to my DSM using Raster Calculator, and it completed fine, but when I try to use the new raster as a surface, it doesn't work as expected.

I thought it would look exactly the same as the DSM, just with an added building (although the stadium did already exist).

Screenshots attached showing just the DSM with aerial draped over (DSM1), then the newly created raster (DSM_and_Stadium). Perhaps my settings weren't correct when creating the raster from the polygon to raster tool?

Re: 3D Scene - Drape image over 3D layers?

JayantaPoddar — Wed, 23 Jun 2021 15:52:27 GMT

"DSM_and_Stadium.jpg": Is the aerial image draped over the newly created DSM?

Re: 3D Scene - Drape image over 3D layers?

Daniel_Hardwick — Wed, 23 Jun 2021 15:55:06 GMT

Yes, the aerial is still turned on. The only difference between them two pictures is one is using the DSM, and the other is using the newly created raster (raster and DSM).

Re: 3D Scene - Drape image over 3D layers?

JayantaPoddar — Wed, 23 Jun 2021 16:11:28 GMT

I hope the coordinate system of all the involved datasets (Raster/ Vector) are same.

How do the Min/Max value range of both the DSM and revised DSM compare to each other? Could you click on other parts of the revised DSM (where there is no building), to check if it gives same value(s) as the original DSM?

While executing Polygon to Raster, define the DSM as the Snap Raster (Tool Environments > Raster Analysis > Snap Raster).

Re: 3D Scene - Drape image over 3D layers?

Daniel_Hardwick — Thu, 24 Jun 2021 10:28:00 GMT

Thanks Jayanta.

The Coordinate system is all the same (British National Grid).

I have brought the original DSM and revised DSM into a new 2D Project, and the revised one only seems to cover the area where the stadium is. Even though it was created using the stadium raster + DSM tile. So I don't know why that is. I have checked the range of values of the two on the stadium itself (since that's the only area which is covered in both), and they differ considerably. The pop for the DSM shows values around 22-27, but the revised DSM shows stretch pixel value of around 42-46. Could it be that the revised DSM is adding up the DSM height, and also the rasterized polygon?

I don't seem to have the snap raster tool, so I don't think I can do that.

Re: 3D Scene - Drape image over 3D layers?

JayantaPoddar — Thu, 24 Jun 2021 11:36:26 GMT

What does the expression look in Raster Calculator?

Try a similar expression to this

Con(IsNull("StadiumRas"), "DSM", ("DSM"+"StadiumRas"))

Re: 3D Scene - Drape image over 3D layers?

Daniel_Hardwick — Thu, 24 Jun 2021 12:21:46 GMT

The expression was very simple:

"Riverside_raster" + "[ELEVATION_SURFACE]\CopyRaster_OutRasterdataset_nz5020_DSM_50CM"

Using your expression it looks like:

Con(IsNull("Riverside_raster"), "[ELEVATION_SURFACE]\CopyRaster_OutRasterdataset_nz5020_DSM_50CM", ("[ELEVATION_SURFACE]\CopyRaster_OutRasterdataset_nz5020_DSM_50CM"+"Riverside_raster"))

This ran fine, but the output I think is still the same. The pixel value is still showing around 46 and the extent once again seems to be only the stadium raster and not the coverage of the whole DSM.

Looking at this newly created DSM, it does look like the rasters have been combined and the height doubled. Screenshot shows left image of newly created combined DSM, and just the original DSM on right (same scale used).

Is my best option to create a DTM and then try doing this? With the buildings not being included in the DTM then the added stadium raster might work?

Re: 3D Scene - Drape image over 3D layers?

Daniel_Hardwick — Fri, 25 Jun 2021 08:53:48 GMT

Just to add to this.

I have now downloaded a DTM (asc format), converted into raster and used that as an elevation surface.

I then also added in the Stadium raster which I create a few posts ago, as another elevation surface, and that works well, image attached.

Out of interest I wanted to try the raster calculator again, as it ran successfully before but didn't give the expected result. I ran the Raster Calculator tool to combine the DTM and the stadium raster and used the output as the elevation surface. The newly created raster still doesn't seem to include the rest of the DTM surface, it only covers the stadium, so not sure if this is any difference from just using the stadium raster as a surface, as the output doesn't seem to include anything from the DTM.

With the raster calculator not working as expected, it looks like I could just use the built in ground elevation surface and just add in any rasterized polygons. I don't need to use my own DTM. Obviously if the raster calculator worked as expected then having the DTM and the mastermap rasters in a single file would have been nice, but it should still work adding them in as two separate surfaces.

This is probably as close as I am going to get. If I wanted to create a fuller scene with more buildings it looks like I will have to rasterize the building polygons that I am interested in to allow me to drape aerial imagery over them.