topic Re: Viewshed observer Height in ArcGIS JavaScript Maps SDK Questions

Viewshed observer Height

jaykapalczynski — Sun, 12 Dec 2021 07:19:40 GMT

Using this: CreateViewshed | API Reference | ArcGIS API for JavaScript 3.23

I think I am defining the parameters for Height incorrectly and cant seem to find them in the documentation

vsHeight.height

"observerHeight": vsHeight,
"observerHeightUnits": "feet"

Trying this:

<input type="radio" name="DistanceVS" value="1" checked="checked">1 Mile</input>
<input type="radio" name="HeightVS" value="1" checked="checked">1 Meter</input>


var radios = document.getElementsByName('DistanceVS');
var w = parseInt(radios);
vsDistance.distance = (w);

var height = document.getElementsByName('HeightVS');
var h = parseInt(height);
vsHeight.height = (h);
            
vsDistance.units = "esriMiles";
var params = {
    "Input_Observation_Point": featureSet,
    "Viewshed_Distance": vsDistance,
    "observerHeight": vsHeight,
    "observerHeightUnits": "feet"
};‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: Viewshed observer Height

jaykapalczynski — Sun, 12 Dec 2021 07:19:43 GMT

I think I got it working....Can someone pass their eyes over this and see if they see anything out of place...

//SNIP

var vsDistance = new LinearUnit();
var vsHeight = new LinearUnit();
             
       
var radiodistance = document.getElementsByName('DistanceVS');
var w = parseInt(radiodistance);
vsDistance.distance = (w);

var radioheight = document.getElementsByName('HeightVS');
var h = parseInt(radioheight);
vsHeight.distance = (h);

               
vsDistance.units = "esriMiles";
vsHeight.units = "esrifeet";
          
var params = {
    "Input_Observation_Point": featureSet,
    "Viewshed_Distance": vsDistance,
    "observerHeight": vsHeight
};
 gp.execute(params, drawViewshed, errorViewShed);
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: Viewshed observer Height

jaykapalczynski — Wed, 20 Dec 2017 17:26:12 GMT

No I dont think I have it...seems that the user defined input is not being used in the Viewshed.

I changed them and ran from the same point and get the same result no mater what distance I choose or what height I try and push to the variables. hmmmm

Doesnt seem like I am getting the value of the radio buttons to the variable and then to the Params

Re: Viewshed observer Height

RobertScheitlin__GISP — Wed, 20 Dec 2017 17:26:39 GMT

Looks good to me.

Re: Viewshed observer Height

jaykapalczynski — Wed, 20 Dec 2017 17:31:56 GMT

If I add an alert on the

var radiodistance = document.getElementsByName('DistanceVS');
var w = parseInt(radiodistance);
alert(w);

I get

Re: Viewshed observer Height

jaykapalczynski — Wed, 20 Dec 2017 17:35:15 GMT

If I alert here

var radiodistance = document.getElementsByName('DistanceVS');
alert(radiodistance);

if gives me:

Re: Viewshed observer Height

RobertScheitlin__GISP — Wed, 20 Dec 2017 17:50:51 GMT

Jay,

So the issue is you are returning the dom element and not the value:

var height = document.getElementsByName('HeightVS').value;

Re: Viewshed observer Height

jaykapalczynski — Wed, 20 Dec 2017 18:14:07 GMT

I get the below response for each of the alerts below.

undefined

NaN

var radiodistance = document.getElementsByName('DistanceVS').value;
alert(radiodistance);
var w = parseInt(radiodistance);
alert(w);
vsDistance.distance = (w);

Re: Viewshed observer Height

RobertScheitlin__GISP — Sun, 12 Dec 2021 07:19:45 GMT

Jay,

Well I really needed to look over your code better... You are using

var radiodistance = document.getElementsByName('DistanceVS')

document.getElementsByName returns an array/collection of node that have that name. You can use this but the more standard way is to give you dom elements an id and then use document.getElementById('DistanceVS').value.

<input type="radio" id="DistanceVS" value="1" checked="checked">1 Mile</input>
<input type="radio" id="HeightVS" value="1" checked="checked">1 Meter</input>


var radios = dom.byId('DistanceVS').value;
var w = parseInt(radios);
vsDistance.distance = (w);

var height = dom.byId('HeightVS').value;
var h = parseInt(height);
vsHeight.height = (h);
            
vsDistance.units = "esriMiles";
var params = {
    "Input_Observation_Point": featureSet,
    "Viewshed_Distance": vsDistance,
    "observerHeight": vsHeight,
    "observerHeightUnits": "feet"
};‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: Viewshed observer Height

jaykapalczynski — Sun, 12 Dec 2021 07:19:48 GMT

I am trying to give the user a selection of radio buttons to choose the distsance
Grab that value in JS and write it to a variable
Use that variable in as a parameter for Viewshed Distance and Viewshed Observer Height

Not sure why I cant get the radio button variable. Not sure if I use ID or NAME...I dont think I can use ID with a radio button selection

<div>
   <input type="radio" id="DistanceVS" name="DistanceVS" value="1" checked="checked">1 Mile</input>
   <input type="radio" id="DistanceVS" name="DistanceVS" value="3" >3 Miles</input>
   <input type="radio" id="DistanceVS" name="DistanceVS" value="5" >5 Miles</input>
   <input type="radio" id="DistanceVS" name="DistanceVS" value="10" >10 Miles</input>
</div>

<div>
   <div>
      <input type="radio" name="HeightVS" value="1" checked="checked">1 Meter</input>
      <input type="radio" name="HeightVS" value="3" >3 Meters</input>
   </div>
   <div>                                   
      <input type="radio" name="HeightVS" value="5" >5 Meters</input>
      <input type="radio" name="HeightVS" value="10" >10 Meters</input>
   </div>
</div>

‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

function computeViewShed(evt) {
   map.graphics.clear();
   var pointSymbol = new SimpleMarkerSymbol();
   pointSymbol.setSize(14);
   pointSymbol.setOutline(new SimpleLineSymbol(SimpleLineSymbol.STYLE_SOLID, new Color([255, 0, 0]), 1));
   pointSymbol.setColor(new Color([0, 255, 0, 0.25]));

   var graphic = new Graphic(evt.mapPoint, pointSymbol);
   map.graphics.add(graphic);

   var features = [];
   features.push(graphic);
   var featureSet = new FeatureSet();
   featureSet.features = features;
   var vsDistance = new LinearUnit();
   var vsHeight = new LinearUnit();



// TRYING TO GRAB THE VALUE AND ASSIGN TO VARIABLE AND ALERT
   var radiodistance = document.getElementsByName('DistanceVS').value;
// OR
   var radiodistance = dom.byId('DistanceVS').value;

   alert(radiodistance);
   var w = parseInt(radiodistance);
   alert(w);
   vsDistance.distance = (w);


   // SAME AS THE ABOVE DISTANCE VARIABLE
   var radioheight = document.getElementsByName('HeightVS').value;
   var h = parseInt(radioheight);
   vsHeight.distance = (h);
     

          
   vsDistance.units = "esriMiles";
   vsHeight.units = "esriMeters";
   var params = {
      "Input_Observation_Point": featureSet,
      "Viewshed_Distance": vsDistance,
      "observerHeight": vsHeight
};
  gp.execute(params, drawViewshed, errorViewShed);
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: Viewshed observer Height

RobertScheitlin__GISP — Sun, 12 Dec 2021 07:19:51 GMT

Jay,

So if you are trying to get the value of a selected radio in a group of radios then this is what you need:

HTML

<div>
   <input type="radio" name="DistanceVS" value="1" checked="checked">1 Mile</input>
   <input type="radio" name="DistanceVS" value="3">3 Miles</input>
   <input type="radio" name="DistanceVS" value="5">5 Miles</input>
   <input type="radio" name="DistanceVS" value="10">10 Miles</input>
</div>

<div>
   <div>
      <input type="radio" name="HeightVS" value="1" checked="checked">1 Meter</input>
      <input type="radio" name="HeightVS" value="3">3 Meters</input>                                  
      <input type="radio" name="HeightVS" value="5">5 Meters</input>
      <input type="radio" name="HeightVS" value="10">10 Meters</input>
   </div>
</div>‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

function computeViewShed(evt) {
   map.graphics.clear();
   var pointSymbol = new SimpleMarkerSymbol();
   pointSymbol.setSize(14);
   pointSymbol.setOutline(new SimpleLineSymbol(SimpleLineSymbol.STYLE_SOLID, new Color([255, 0, 0]), 1));
   pointSymbol.setColor(new Color([0, 255, 0, 0.25]));

   var graphic = new Graphic(evt.mapPoint, pointSymbol);
   map.graphics.add(graphic);

   var features = [];
   features.push(graphic);
   var featureSet = new FeatureSet();
   featureSet.features = features;
   var vsDistance = new LinearUnit();
   vsDistance.units = "esriMiles";
   var vsHeight = new LinearUnit();
   vsHeight.units = "esriMeters";

   var distInt, i;
   var distVS = document.getElementsByName('DistanceVS');
   for (i = 0; i < distVS.length; ++i) {
     if (distVS[i].checked) {
       distInt= parseInt(distVS[i].value);
     }
   }
   alert(distInt);
   vsDistance.distance = (distInt);

   var heightInt;
   var heightVS = document.getElementsByName('HeightVS');
   for (i = 0; i < heightVS.length; ++i) {
     if (heightVS[i].checked) {
       heightInt= parseInt(heightVS.value);
     }
   }
   alert(heightInt);
   vsHeight.distance = (heightInt);
         
   vsDistance.units = "esriMiles";
   vsHeight.units = "esriMeters";
   var params = {
      "Input_Observation_Point": featureSet,
      "Viewshed_Distance": vsDistance,
      "observerHeight": vsHeight
  };
  gp.execute(params, drawViewshed, errorViewShed);
}
‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: Viewshed observer Height

jaykapalczynski — Sun, 12 Dec 2021 07:19:54 GMT

OK I came to the same realization that I was not handling the radio buttons correctly pertaining to retrieving the values and assigning them to variables.

I came up with something similar and then checked back here to see your response

var RadioDistance = document.getElementsByName('DistanceVS');
var Distance_value;
for(var i = 0; i < RadioDistance.length; i++){
    if(RadioDistance[i].checked){
        Distance_value = RadioDistance[i].value;
    }
}
alert(Distance_value);       
vsDistance.distance = (Distance_value);‍‍‍‍‍‍‍‍‍

MY question is....

Am I using the correct parameter to change the observation height....

I clicked on an intersection with a 10 mile distance and 1 meter height

I then clicked on the same intersection with a 10 mile distance and a 1000 meter height.

The result is the same...I find that hard to believe the Viewshed would be the same at 1 meter and 1000 meters.

Am I using the wrong parameter or setting it incorrectly? I want the Viewshed to take into account the increase elevation of an observation point and then adjust the viewshed result.

Say I was standing on a 80 ft tower, what could I see

I will tag yours as the answer.

Re: Viewshed observer Height

RobertScheitlin__GISP — Wed, 20 Dec 2017 20:55:29 GMT

Jay,

I now see that you are mixing two different things here.

You are using a GP that has set end defined parameters

then you are referencing the

CreateViewshed | API Reference | ArcGIS API for JavaScript 3.23

Analysis dijit which is a whole other thing.

You need to look at the GP rest end point and see what parameters and parameter types it is expecting.

Re: Viewshed observer Height

jaykapalczynski — Wed, 20 Dec 2017 21:10:51 GMT

Using this ESRI service...not sure how to access it to see these parameters

https://sampleserver6.arcgisonline.com/ArcGIS/rest/services/Elevation/ESRI_Elevation_World/GPServer/Viewshed

know any more that are out there for free?

Re: Viewshed observer Height

RobertScheitlin__GISP — Sun, 12 Dec 2021 07:19:57 GMT

Jay,

Here is the json for that service and there is no parameter to observer height.

I am not aware of another free service that allows for that level of control.

{
 "name": "Viewshed",
 "displayName": "Viewshed",
 "description": "Calculates the viewshed of a point given a user defined location and viewing distance.",
 "category": "",
 "helpUrl": "https://sampleserver6.arcgisonline.com/arcgis/rest/directories/arcgisoutput/Elevation/ESRI_Elevation_World_GPServer/Elevation_ESRI_Elevation_World/Viewshed.htm",
 "executionType": "esriExecutionTypeSynchronous",
 "parameters": [
  {
   "name": "Input_Observation_Point",
   "dataType": "GPFeatureRecordSetLayer",
   "displayName": "Input_Observation_Point",
   "description": "The input location from which the viewshed should be calculated.",
   "direction": "esriGPParameterDirectionInput",
   "defaultValue": {
    "displayFieldName": "",
    "geometryType": "esriGeometryPoint",
    "spatialReference": {
     "wkid": 54003,
     "latestWkid": 54003
    },
    "fields": [
     {
      "name": "OBJECTID",
      "type": "esriFieldTypeOID",
      "alias": "OBJECTID"
     },
     {
      "name": "OffsetA",
      "type": "esriFieldTypeSmallInteger",
      "alias": "OffsetA"
     }
    ],
    "features": [],
    "exceededTransferLimit": false
   },
   "parameterType": "esriGPParameterTypeRequired",
   "category": ""
  },
  {
   "name": "Viewshed_Distance",
   "dataType": "GPLinearUnit",
   "displayName": "Viewshed_Distance",
   "description": " The maximum distance from the input point for which the viewshed should be calculated. The maximum allowed distance is 20000 meters.",
   "direction": "esriGPParameterDirectionInput",
   "defaultValue": {
    "distance": 15000,
    "units": "esriMeters"
   },
   "parameterType": "esriGPParameterTypeRequired",
   "category": ""
  },
  {
   "name": "Viewshed_Result",
   "dataType": "GPFeatureRecordSetLayer",
   "displayName": "Viewshed_Result",
   "description": "The resulting viewshed feature class given the user location and maximum distance.",
   "direction": "esriGPParameterDirectionOutput",
   "defaultValue": {
    "displayFieldName": "",
    "geometryType": "esriGeometryPolygon",
    "spatialReference": {
     "wkid": 54003,
     "latestWkid": 54003
    },
    "fields": [
     {
      "name": "OBJECTID",
      "type": "esriFieldTypeOID",
      "alias": "OBJECTID"
     },
     {
      "name": "Id",
      "type": "esriFieldTypeInteger",
      "alias": "Id"
     },
     {
      "name": "grid_code",
      "type": "esriFieldTypeInteger",
      "alias": "grid_code"
     },
     {
      "name": "Shape_Length",
      "type": "esriFieldTypeDouble",
      "alias": "Shape_Length"
     },
     {
      "name": "Shape_Area",
      "type": "esriFieldTypeDouble",
      "alias": "Shape_Area"
     }
    ],
    "features": [],
    "exceededTransferLimit": false
   },
   "parameterType": "esriGPParameterTypeRequired",
   "category": ""
  }
 ]
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: Viewshed observer Height

jaykapalczynski — Fri, 22 Dec 2017 14:58:19 GMT

OK thanks for all your help....much appreciated...