Hi all !
Could someone experienced explain me how to get rid of this black vertical bars (see attachment) I getiing after applying spotlight tool to image with black backgoud ? Black backgound works as mask in this case to prevent rising of all surface.
I suppose that reason is interpolating from exactly black (0,0,0) to color at the border of image, but don’t know hot to prevent it.
Thanks in advance.
ZB understands pure black as transparent. Never understood that one myself …
Polypainting, masking… all that stuff we applying to vertices (points on Zbrush language).
In 3d space you cannot paint neighboring polygons in different clear colors, they will always have mix color from their vertecies.
Same for masking, from full masked (black) polygon to unmasked (white) one there must be some gradient poly(s).
You could separate polypainting process from modeling, eg first project color without black, than use your image with black for sculpting (maskling, modeling). I don’t usin spotlight so can’t be more specific.
(Lot of questions here on that subject, like: “can’t make sharp mask, clear polypaint…” and solution: “higher resolution” - true but trying some things on low res. level can be realy helpful)
ZB understands pure black as transparent. Never understood that one myself …
You mean texture map transparency?
Look at that like masking, black blocking (masking) mesh visibility so it’s transparent
And it’s not just zbrush privilege, and it doesn’t have to be pure black, and that can be very useful 
@Modos … 1st I do perfectly understand what polypainting is and how it works … 2nd I have no clue what you are talking about especially when you say that you don’t use Spotklight 
ZBrush is the only app I have ever come across where pure black in a texture means transparency. Specifically in Spotlight that can be very annoying when you want to paint a texture. If anyone could explain that to me/us I would be delighted to finally learn about the “why”
@Modos,
Thank you for suggestions - I was using separate process (modelling + polypainting) before but huge advantage of Spotlight for me is ability to combine them in one step while doing reliefs from sources like attached.
Now I am doing manual clean-up with Smooth brush after Spotlighting, but it is annoying and time consuming.
Will continue looking for solution.
Easiest way is to probably use goZ with photoshop or the like, that way you’re not dependent on pure black as a mask.
You could also use a slice brush and cut off all the unwanted areas from a sideview and then extrude the edge down to make up the difference while keeping the polypaint color.
eh, my 2 cents.
Thank you, @beta, I will try GoZ with PS