Confusion in creating vector layer

Question

I have a confusion in creating vector layer. I have source data in GeoJSON and in EPSG:3857 (my map view is already in EPSG:3857).

Since it is in EPSG:3857, I thought it is not necessary to use any projection exp.

But vector is not displayed.

What I did:

 var vectorSourceCenter = new ol.source.Vector({
                features: features,
                //featureProjection: 'EPSG:3857'
                //projection: 'EPSG:3857'
   });

   var vectorCenterLayer = new ol.layer.Vector({
                source: vectorSourceCenter
   });

   map.addLayer(vectorCenterLayer );

Answer 1

Have you tried something like this in your code ?

source=new ol.source.Vector({
                    projection : 'EPSG:3857',
                    url: 'yourfile.geojson',
                format: new ol.format.GeoJSON()
                    });
layer=new ol.layer.Vector({
                source: source,
            })
    });

Then adding it to the map:

map.addLayer(layer);

I had a problem like this before but with 'EPSG:4326' and it turned out I was inversing the lat long in my layer source.