topic Re: 3D Aerial Imagery - Trees/Forests in 3D Questions

3D Aerial Imagery - Trees/Forests

TimHughes — Wed, 01 Jan 2014 20:05:41 GMT

Hi,

I have been given an animation of a new road design. In this animation they have used aerial imagery as the base map. This looks very realistic. When I try to create something similar, the trees look more like marshmallows! I have draped the imagery over a DEM.

I know I am doing something wrong, but can someone shed some light as to what I am doing wrong? The attachment is from ArcScene.

Thank you in advance for any help.

Regards

Re: 3D Aerial Imagery - Trees/Forests

JeffreySwain — Fri, 03 Jan 2014 10:24:03 GMT

You might get a better result by making the Raster Resolution of the raster you are draping match the original raster resolution. By default, the raster resolution will be more coarse than the original to save processing time. However, the best option may be to use the bare earth DEM and then add 3d Symbology or multipatches of the trees to get the best effect.

Re: 3D Aerial Imagery - Trees/Forests

TimHughes — Fri, 03 Jan 2014 14:34:55 GMT

I am happy with creating multipatch data and using 3D symbols, however, this isn't really feasible over such a large area (as far as I know...?).

I am finding it hard to produce a really nice animation over a larger landscape 😞

Re: 3D Aerial Imagery - Trees/Forests

larryzhang1 — Wed, 08 Jan 2014 10:46:49 GMT

Hi,

I have been given an animation of a new road design. In this animation they have used aerial imagery as the base map. This looks very realistic. When I try to create something similar, the trees look more like marshmallows! I have draped the imagery over a DEM.

I know I am doing something wrong, but can someone shed some light as to what I am doing wrong? The attachment is from ArcScene.

Thank you in advance for any help.

Regards

From your snapshot, it looks that your �??DEM�?? is not �??bare�?? earth surface, which might be directly derived from DSM (Digital Surface Model for stereo-pair, or Dense Surface Model for LiDAR).

Generally, DEM /DTM data should be referred to bare elevation, which should exclude any features like trees, buildings, tanks, and others from DSM.

+++++++++

To accurately generate DEM from DSM, it is advisable to use the third-party packages like Leica, in particular, used in urban and civil-engineering applications�?�

To build any CityModel (muiltipatch), which could include any 3D trees and buildings, it is good idea to use ESRI CityEngine�?�

Re: 3D Aerial Imagery - Trees/Forests

larryzhang1 — Mon, 13 Jan 2014 10:00:30 GMT

...

To accurately generate DEM from DSM, it is advisable to use the third-party packages like Leica, in particular, used in urban and civil-engineering applications�?�

To build any CityModel (muiltipatch), which could include any 3D trees and buildings, it is good idea to use ESRI CityEngine�?�

Ok,

If planning to directly derive 3D buildings/trees from 'cloud' point data (that is, from DSM, which can be from stereo-pair or Lidar), you can use ENVI LiDAR /TerraScan. In this way, ESRI CityEngine is not required...

[INDENT]For reference on ENVI LiDAR, pls go to the link at http://www.exelisvis.com/docs/tutorialprocessdatasample.html[/INDENT]

Re: 3D Aerial Imagery - Trees/Forests

808707 — Mon, 13 Jan 2014 13:39:05 GMT

I could be wrong but is it something to do with maximum cell size that you can display in ArcScene?

I had a similar issue where I had some 10cm resolution aerial imagery but it could only be displayed at 1m resolution in Arcscene (Of course if someone knows a way around this then please let me know!).

Re: 3D Aerial Imagery - Trees/Forests

larryzhang1 — Tue, 14 Jan 2014 02:27:17 GMT

I could be wrong but is it something to do with maximum cell size that you can display in ArcScene?

I had a similar issue where I had some 10cm resolution aerial imagery but it could only be displayed at 1m resolution in Arcscene (Of course if someone knows a way around this then please let me know!).

You can try to display in ArcGlobe, even ArcGIS Explorer (not ArcScene).

+++++++
It looks that except for 3D CityModel and 'derived' surface/TIN, ArcScene wouldn't give too much detailed display for raster images, ...

[INDENT] For raster images, mostly, around 40-m after resample, no mater how good your workstation is, from our practice. I guess, that could be system-related design matter; [/INDENT]

[INDENT]For raster surface in ArcScene, go to the relevant reference in ArcGIS...[/INDENT]

So, advisable to use ArcGlobe for raster images, which will give very-detailed visualization for full-scale airphoto and raster surface, in addition to 3D multipatch & full-scale terrain surface.

Re: 3D Aerial Imagery - Trees/Forests

GeospatialTechnology — Tue, 14 Jan 2014 09:16:01 GMT

Thanks hlzhang301 I'll give it a go in ArcGlobe.