Timeline for Using 3D Analyst Line of Sight?
Current License: CC BY-SA 3.0
9 events
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| Jun 24, 2014 at 5:26 | comment | added | Chris W | @LisaSH At this point screenshots of your results or sample data are needed for me to be able to suggest anything further. I did note at the How Line of Sight Works page a line that says "If no multipatch feature is provided, the output line is draped onto the surface." Are you sure the analysis is ignoring offsets, or is it just the output line itself? | |
| Jun 23, 2014 at 7:57 | comment | added | lisagravy | Yeah I've rerun line of sight after fixing my sight lines, and just the same result. I wouldn't even mind if the output was a 2D line, it just doesn't seem to be running the analysis on the height of my targets, just the base height. I know what you mean, there seems to be a variety of ways of doing this which can be easily confused... | |
| Jun 20, 2014 at 20:29 | comment | added | Chris W | @LisaSH Did you reconstruct your sight lines before using line of sight (or rerun line of sight afterward)? I'm not sure (again, not actively testing) but LoS output may be 2D regardless of input - check, and if so you'd have to then convert those lines to 3D. Part of the problem with all of this is you can set heights in several places and ways, and apply offsets as well. All the various steps and interacting options get difficult to track when you tinker here or there. | |
| Jun 20, 2014 at 20:22 | history | edited | Chris W | CC BY-SA 3.0 |
added addtional information
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| Jun 20, 2014 at 9:56 | comment | added | lisagravy | Ahh, ok, so there are default Z height field titles that take precedence over your specified input in 'Construct Sight Lines'... if I change my 'total_height' field to 'Spot' it reads it automatically, the presence of a 'Z' field was overriding 'total_height', even though I was selecting that one. Now in ArcGlobe I have 3D lines running from +2m above terrain to +130m above terrain. Sadly this doesn't seem to fix my Line of Sight output, that one is still hugging the terrain and doesn't seem to be taking account of the target 'Spot' height at all... | |
| Jun 20, 2014 at 9:44 | comment | added | lisagravy | Also, when I open the lines of sight in ArcGlobe they are clinging to the terrain, even when set to float. There's presumeably a setting or input I'm missing somewhere... | |
| Jun 20, 2014 at 9:38 | comment | added | lisagravy | Ahhh ok, thanks! This is better, I am now getting at least red and green lines which looks much more like what I've been expecting. However.... they're still not right?! I have used Add Surface Information to obtain a Z field, and then created another field to add my Z field and my offset field together to create an overall height above the terrain, and this is what I'm using. The answers I'm getting though look like they are just to the ground level of my targets rather than my ground+offset (+130m)? I'm specifying my edited field in the 'target height field' space, rather than Z. Any ideas? | |
| Jun 19, 2014 at 21:07 | history | edited | Chris W | CC BY-SA 3.0 |
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| Jun 19, 2014 at 21:01 | history | answered | Chris W | CC BY-SA 3.0 |