Hey,
in case this has been already discussed somewhere in this forum, please redirect me as I couldnt find anything about this topic using the search function.
I wold realy appreciate some help on how to use alphas in Zbrush. I would like to do some ornaments and reliefs on stone (roman architecture).
But I cant seem to find good alphas for it nor am I able to create them properly in PS. I am not sure what the important points for an alpha are. Should they consist only of black and white or are grey shades ok, too?
I only found some fast tutorials Vids and it always looks so easy.. they just bring out the alpha on a mesh and its almost perfect.
My result is more of a blobby something or something super sharp you cant identify.
Any help would be really appreciated, perhaps you also know some links to a tutorial Vid?
thanks a lot in advance.
.patient
Replies
So, if you have one that's only completely hard black and white, you'll be pushing the white silhouette into our out from your sculpt. Adding in grey blending between them will let you smooth out the shape and get rounder/more detailed ones. Just that simple.
Of course, any noise within the image or compression chopping it up will leave a noisy/bumpy surface, so if you're getting that, you may need to clean it up more in PS, or on the sculpt afterwards.
Just, look a bit more into heightmaps
But yeah buying a whole (eventhough very good DVD) just to take a look at one workflow is kinda meh.
I guess you know these already:
[ame]http://www.youtube.com/watch?v=WZVQ6hH5gaw[/ame]
[ame="http://www.youtube.com/watch?v=R_SXArWeCFU"]How to make a Zbrush Alpha - YouTube[/ame]
maybe some of the stuff from this is also applicable:
[ame="http://www.youtube.com/watch?v=wGLPppTYSZo"][Texture] Alpha Maps - YouTube[/ame]
Doesn't ZBrush make use of fall offs for the brushes? Why are the "falloffs" essentially being painted into the alpha's directly?
Anyway an alternative way to make an alpha would be to sculpt a piece and bake a heightmap from it.
Since you are not entirely sure what an alpha is I suggest doing it this way. The reason why, is because you will be familiar with what you have sculpted and once you bake it, you will know exactly what the alpha/heightmap is doing.
Basically an alpha is like a heightmap/bump map.
On how they are used. An "alpha" map is mostly used to mask off areas of.. something. In case of transparency and transparency maps the map is used to mask off opaqueness. Black is no and white is yes. Anything in between will be a percentage of what will be masked. So a 50% grey would be 50% "yes".
In case of Alphas in ZBrush they are used to mask off a part of your brush strength or draqRect or something (I am not a Zbrush user). So if your brush strength was set to 1 or 100% a completely white(100%) alpha ( or no alpha at all) would mean the strength you apply via the brush is 100%, if it is black the strength that is applied is 0%. Anything in between is a percentage according the brightness of that area. So a 50% grey would mean the strength of the brush will be 50% as well.