here you can see the ovale where you can see the afterimage filter; so it look like it follow the cursor because it works like this : the filter is aplied stronger around the cursor.but i couldnt find a way to make is visible in a perfect circle.
float distance = distance(vUv, mouse);
if (distance < radius) {
texelOld = damp 1.2* when_lt( texelOld, 0.4 ); ///the effect is stronger in tha area
} else {
texelOld *= damp * 0.1 * when_lt( texelOld, 0.9 );', ///the effect is nearly to 0
}
the problem is not specific to three.js , its just i cant find a way to have an area perfectly round. And the more stronger i use the effect the more you see the ovale shape. i should find a way to take about the ratio of my screen.
Its maybe not the best way to make an effect that look like following the cursor but that’s the only way that came to my mind 