When to pass reprojectionerrorthreshold option in OpenLayers?

When to pass reprojectionerrorthreshold option in OpenLayers?

In case a different threshold needs to be defined for different sources, the reprojectionErrorThreshold option can be passed when constructing the tile image source. The reprojection algorithm uses inverse transformation (from view projection to data projection ).

How does raster reprojection work in OpenLayers?

Raster Reprojection. OpenLayers has an ability to display raster data from WMS, WMTS, static images and many other sources in a different coordinate system than delivered from the server. Transformation of the map projections of the image happens directly in a web browser.

How to switch the projection used to display the map?

To switch the projection used to display the map you have to set a new ol/View with selected projection on the ol/Map: When reprojection is needed, new tiles (in the target projection) are under the hood created from the original source tiles.

What does the calculatesourceresolution function do in OpenLayers?

The ol/reproj~calculateSourceResolution (sourceProj, targetProj, targetCenter, targetResolution) function calculates the ideal value in order to achieve pixel mapping as close as possible to 1:1 during reprojection, which is then used to select proper zoom level from the source.

How can I reproject an image in Ol / view?

The API usage is very simple. Just specify proper projection (e.g. using EPSG code) on ol/View: If a source (based on ol/source/TileImage or ol/source/Image) has a projection different from the current ol/View ’s projection then the reprojection happens automatically under the hood.

How is the precision of a reprojection limited?

The precision of the reprojection is then limited by the number of triangles. The reprojection process preserves transparency on the raster data supplied from the source (png or gif) and the gaps and no-data pixels generated by reprojection are automatically transparent.

How does OpenLayers work with raster data?

OpenLayers has an ability to display raster data from WMS, WMTS, static images and many other sources in a different coordinate system than delivered from the server. Transformation of the map projections of the image happens directly in a web browser.

What does true and false mean in OpenLayers?

If true, the view will always animate to the closest zoom level after an interaction; false means intermediary zoom levels are allowed. If true, the resolution min/max values will be applied smoothly, i. e. allow the view to exceed slightly the given resolution or zoom bounds.

What is the max resolution for OpenLayers view?

If unspecified it is calculated in such a way that the projection’s validity extent fits in a 256×256 px tile. If the projection is Spherical Mercator (the default) then maxResolution defaults to 40075016.68557849 / 256 = 156543.03392804097. The minimum resolution used to determine the resolution constraint.

What does alert ( ) do in OpenLayers 3?

For now it is in an alert () call just for experimenting and troubleshooting. When this function is called it returns values that are far away or totally wrong from the actual boundaries of the projection, for example when zoomed in over a small city in the mid part of Sweden it returns the following extent: