Painting cracks on a wall without raised area around them for brush shape

[rengsto]

I'm sculpting a weathered, cracked wall and want to build out a displacement map from it. On certain areas of the wall I want to sculpt in some cracks. I'm painting the cracks in using a mask (photo based image file), and I've tweaked the mask image in Photoshop so there are no values brighter than middle grey--only middle grey and darker. When I paint the cracks in (See "A" on attached screenshot) they are there...but also there is the raised area around the cracks (See "B" on screenshot) from what I think is the brush shape? 

 

I've tried using various voxel tools...I'm using extrude because it doesn't build up like the others when you hover over an area.

 

Other brushes have a more gradual fade-off than the one I'm using, but still they do pop out the surface.

 

I thought maybe making a .psd brush with a middle grey height-map might do it, but that brush doesn't paint the detail of the cracks, only paints a slight indentation for the brush (which I imagine it shouldn't be doing?!). 

 

Is there some way I can scult in the cracks using the mask image on certain areas of the wall without raising the area around the crack?

 

Thanks for your thoughts on this...

Edited January 12, 2014 by rengsto

[TimmyZDesign]

Try out surface mode instead of voxel mode for better control.

[Psmith]

When using a mask, any gray areas will produce positive or negative relief.  Only pure black will not produce a relief (or white, if you are holding down the Ctrl key).

 

You could produce a mask which is derived from a grayscale image - containing only posterized white and black - to produce a relief of cracks on a surface.

 

 

Greg Smith

[ScrotieFlapWack]

With material masks is it possible to make these in any other program? Or is it just Photoshop? I use a program called Black Ink made by Bleank and I don't think that it is possible to make greyscale images in there for material masks.

[Malo]

It makes no difference what program you use, as log as you could paint black and white.

Everything between black and white (grey) is for different high informations between 0% and 100%

[ScrotieFlapWack]

It makes no difference what program you use, as log as you could paint black and white.

Everything between black and white (grey) is for different high informations between 0% and 100%

 

Ahh I see, I didn't know this. Would I need to export as a certain file type to use?

[Malo]

Not realy.

Klick on the +New field in Masks and you could see all fileformats that are supportet.

jpg, png, obj and a lot of more stuff.

[alvordr]

There are many alternatives to Photoshop for this kind of thing, both free and at a cost.  People often default to Photoshop because of it's maturity and features.  However, folks also use vector-based programs to created clean-lined images.  Photos are also great.  Programs like PixPlant, CrazyBump, Substance Designer, and Genetica (to name a few) are also able to help create the maps you need for specularity, bump/normal/height, diffuse, and/or displacement and some even do procedural texture generation.  I looked at Black Ink, despite having Photoshop, but found it's demo made me realize it's not mature enough to be a real competitor in this space.  My favorite free graphics program is InkScape.  It's used for vector-based graphics creation, but quite useful for this kind of thing.