add draftlog and address pr feedback

Author: dmyronuk

draftlogs/6581_fix.md

@@ -0,0 +1 @@
+ - fix scatter3d marker opacity when marker.opacity is set to 0 [[#6581](https://github.com/plotly/plotly.js/pull/6581)]

src/traces/scatter3d/convert.js

@@ -1,7 +1,5 @@
 'use strict';
 
-var isNumeric = require('fast-isnumeric');
-
 var createLinePlot = require('../../../stackgl_modules').gl_line3d;
 var createScatterPlot = require('../../../stackgl_modules').gl_scatter3d;
 var createErrorBars = require('../../../stackgl_modules').gl_error3d;
@@ -405,7 +403,7 @@ proto.update = function(data) {
 
     // N.B. marker.opacity must be a scalar for performance
     var scatterOpacity = data.opacity;
-    if(data.marker && isNumeric(data.marker.opacity)) scatterOpacity *= data.marker.opacity;
+    if(data.marker && data.marker.opacity !== undefined) scatterOpacity *= data.marker.opacity;
 
     scatterOptions = {
         gl: this.scene.glplot.gl,