MTLLoader: Correctly parse emissive coefficient.

[ConradP]

when parsing the MTL file, the ke value doesn't get converted into a array from string, resulting in errors in the rgb value. I think this was a miss from #15367

[jbaicoianu]

Good catch, I didn't notice that the values were being translated there. Do you have any models which use the Ke value this way? All my test models use Ke_map rather than static values.

[ConradP]

I noticed it when I was playing around with this free model I found on turbosquid.
https://www.turbosquid.com/Download/1041070_22559320
the color gets parsed out as { r : '0', g: '.', b:'0'} so it gave the plane a pinkish color.

[mrdoob]

Thanks!