ZBrushCentral

PolyPaint ISSUE: how to use Alpha map for depth but not affect RGB intensity in brush

ZBrush Usage Questions
#1

Is there a way to use an alpha map within a custom brush to control depth but NOT affect the polypaint RGB value?

I am trying to create a set of drag rectangle brushes that use depth and polypaint, but the alpha is causing the polypaint RGB values to be faded (as expected). Is there a way to “turn off” the opacity effect the alpha is having on the RGB? I want to have 100% polypaint color and desired depth in 1 stroke.

A workaround that sort of works but not very well is to turn off zadd after my initial stroke and then “ReplayLast” (under Stroke -> Modifiers) which basically layers on additional polypaint without depth. The problem is that with heavy depth the texture doesn’t stamp back on very accurately and isn’t efficient

The first image below shows my desired polypaint opacity, basically 100% since there is no alpha map.

  1. polypaint_01.JPG

The second image below shows the alpha map giving me the height (zadd) I want, but unfortunately is also affecting the polypaint RGB value which I don’t want.

  1. polypaint_02.JPG

Any help or suggestions with this issue would be awesome!

#2

You could set focal shift to -100. This is the natural way to fade in Zbrush the brushes.
If this is not enough try Brush-Curve and edit the curve to be a flat line in the top to avoid any deformation. This will stop the alpha curving in the corners, that not sure is what you want.

#3

Hi Altea, thanks for the reply. I have the focal shift set to -100 which definitely helps keep the contour of my alpha as showin in the attached image. Setting the brush curve to be straight also helps with the alpha stamp part but has no effect on keeping the alpha from affecting the RGB opacity :frowning:

#4

This little plugin might help. Unzip the file and copy the RepeatTxtr.zsc file to your ZBrush 4R7\ZStartup\ZPlugs64 folder (and ZStartup\ZPlugs as well if you use 32 bit ZBrush). Restart ZBrush.

The plugin adds two buttons, named Store Txtr and Replay Txtr, to the Brush palette Alpha and Texture sub-palette. To use:

  1. Select the texture you want to use in the Texture palette. If you want to use an alpha to affect the texture opacity then select that in the Alpha palette. Also set the Focal Shift how you want as this can be different from the value used for sculpting.
  2. Press the Store Txtr button. This stores those settings.
  3. Now select “Texture off” in the Texture palette, select the Alpha you want to use for sculpting and set any other settings.
  4. Draw one sculpting stroke. (Note that only the last stroke will be replayed by the plugin.)
  5. Immediately press the Replay Txtr button. This repeats the last stroke using just the texture.

Assigning a hotkey to the Replay Txtr button makes this method relatively painless. Note that you should not rotate or move the model between drawing your sculpting stroke and pressing the Replay Txtr button, otherwise you may get unexpected results!

Let me know if it’s of any use.

RepeatTxtr.zip (1.97 KB)RepeatTxtr.zip (1.97 KB)

#5

awesome will try it out

#6

Thanks marcus! This plugin and workflow definitely works better than the “replayLast” technique I mentioned. It especially works AWESOME with Projection Master. I can use ReplayLast to strengthen my depth a few times while in projection master and then use the “replay txtr” from the plugin to add on as much polypaint as I need.

#7

Exactly what i was looking for! It work’s great Thanks

#8

I was wondering if anyone knows if its possible to do the same thing with spotlight? Right now the only way i found is to manually place the texture and alpha on top of each other and draw them on the model. I don’t know if there is a similar function like in the foundry Mari where you place the texture and click to have the new texture snap to the same position. (considering the texture and alpha are the same size)

#9

Sorry for resurrecting this thread.
I have the same problem as the original poster. However I find the plugin to not quite work for me. Depending on the curvature of the mesh and the intensity of my sculpt brush I get a rather severe offset between the sculpt alpha and the RGB texture.

Doing it the other way round however worked much better for me:
First painting the RGB texture and then replaying the stroke with the Zadd alpha. However this plugin does not support this, it seems. Would it be difficult to adapt the plugin? I am rather new to zBrush in general and ZScripting in particular.

Thanks

-k

#10

Hello, the plugin link isn’t working, is it available elsewhere?

Also is there an easier way to do this in 4r8? I feel like this shouldn’t be so hard to do.

#11

The plugin is not working in 4R8P2 :frowning: