---
layout: example.html
title: Shaded Relief
shortdesc: Calculate shaded relief from elevation data
docs: >
  <p>
    This example uses a <code>ol/source/Raster</code> to generate data
    based on another source.  The raster source accepts any number of
    input sources (tile or image based) and runs a pipeline of
    operations on the input data.  The return from the final
    operation is used as the data for the output source.
  </p>
  <p>
    In this case, a single tiled source of elevation data is used as input.
    The shaded relief is calculated in a single "image" operation.  By setting
    <code>operationType: 'image'</code> on the raster source, operations are
    called with an <code>ImageData</code> object for each of the input sources.
    Operations are also called with a general purpose <code>data</code> object.
    In this example, the sun elevation and azimuth data from the inputs above
    are assigned to this <code>data</code> object and accessed in the shading
    operation.  The shading operation returns an array of <code>ImageData</code>
    objects.  When the raster source is used by an image layer, the first
    <code>ImageData</code> object returned by the last operation in the pipeline
    is used for rendering.
  </p>
tags: "raster, shaded relief"
---
<div id="map" class="map"></div>
<table class="controls">
  <tr>
    <td>vertical exaggeration: <span id="vertOut"></span>x</td>
    <td><input id="vert" type="range" min="1" max="5" value="1"/></td>
  </tr>
  <tr>
    <td>sun elevation: <span id="sunElOut"></span>°</td>
    <td><input id="sunEl" type="range" min="0" max="90" value="45"/></td>
  </tr>
  <tr>
    <td>sun azimuth: <span id="sunAzOut"></span>°</td>
    <td><input id="sunAz" type="range" min="0" max="360" value="45"/></td>
  </tr>
</table>