Stencil full of noise

[system]

Hi everyone,

i found a picture on google and want to use it as a stencil.
So here is the picture of my stencil and the result on my mesh.
The mesh has 8 mil. polys, but i sculpted this result at 132 mil HD polys.
I think this is the right way, because it is a big mesh which polys loose themselfes in the big range of the mesh and so they lack in the face for such detailling.

The problem i face is, that with a low z intensity (about 3) of my brush, i don’t really come further in the progress of sculpting. With a higher intensity (15) the result is how you see it on the picture:

First there is too much noise in it.
I saw some tutorials and they took also photo references which wheren’t the best quality, but they got a nice scuplt. By the way, my photo reference is very sharp and in a high resolution.
What i’m doing wrong?

Second, why is there such a “mask” around the brushed area? The RGB is turned of, so is the Polypaint.

Thank you!

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[goast666]

the problem from your stencil is that it is a high quality high res image. This means that it holds a lot of data in the image…that data being the noise that you’re seeing when you sculpt with it. To fix this you can use the blur function in the alpha panel to pull out the high frequency details that are creating the noise.

you can also lower the resolution of the image and apply a small blur to the image inside of photoshop or whatever image editor you choose. Looking at the levels of the image will also help a lot to make your image work best as a stencil.

Most of the time for stencils I won’t use any image over 512 to achieve the best results for your sculpting.

[system]

This were also my considerations. I eliminated the noise two times and used a gaussian blur. The resolution below 512. The new result is here, but it isnt really satisfying.

I also tried another stencil. See below. Here are other artifacts, something like waves or so.

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[zber2]

Because of the high angle of light on your image, it would be difficult to make a good alpha from it unless you repainted the whole thing. I made some adjustments and enlarged it a bit. See if it’s any better for you.

[system]

Nothing as good as the tutorials i saw

And whats about the black mask during the brushing?

Perhaps in the end, this big mess makes the model more realistic? ^^ I can’t evaluate that.

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[goast666]

In the end it looks like you’re asking your stencil to do too much. There is a very large difference between the high and low points on that image that using it for a stencil just isn’t going to give you the results that you want. You can use it as a place holder for all of your sculpting work though. Do a quick placement of the image so you know where the scales are and then build them up using the image as a reference.

I don’t know what black mask you’re talking about, but you can hide the stencil and still have it active with “ctrl+H”

[system]

I tried a professional free gnomon stencil on the back of the model. The totally seen back has 6 mil. polygons. I think this should be enough for this detail.

So i take the alpha, do it to a stencil, place the stencil, deselect the alpha and use a normal brush with Dots and low intensity. Here the results.

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[system]

What you are saying is right. There are very high an low areas. but this isn’t the point, isn’t it? Only the lower part of the stencil has this wide range between high and low and this doesn’t look bad. Here i wrote “nice” on the result. The other parts were i wrote “bad” doesn’t have this high difference in montains and valleys.

The Black mask i mean is shown in the very first picture of the very first comment. Every area i touched with my brush is getting masked black.

[zber2]

The roughness might be due to streched polys (see pictures). As far as the black painting goes, you don’t have RGB on by any chance?

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[system]

You are right, this looks similar.

I saw a trick to avoid that, or to repair the mesh. But i can’t remember the whole process. You have to go to the lowest sub level, but this isn’t possible without loosing all HD layers.

RGB is off, yes. Polypaint also.

[goast666]

what I meant by the difference in high to low isn’t the way you’re thinking.
I meant that the areas in the face that are all mostly white (not in shadow) from your image are going to think they need to be higher than they really should be. There should be a uniform level of contrast to an image you use for a stencil or bump map.

If you look at the stencil for the scales you showed you’ll see that each and every scale is in white at the tip and black at the base, rather uniformly across the image. The image you’re trying to use has high and low values all over the place.

That image also has pixel data in the image that is causing the stair stepping when you sculpt. If you load that alpha and fill the canvas with it and zoom in you’ll see exactly where your stair stepping is occurring.

Remember that stencils aren’t meant to be just a plop down and everything is good, they are better used for guide lines when working.

[system]

@zber2: How did you the scurfs of your"dinocar" in your sketchbook?

@goast666: Oh, i understand.

Unfortunately the tutorial i’am speaking of has a copyright, so i don’t know if i can should a picture from it. Oh but here is an introduction with the stencil in photoshop and the later result of the eye wrinkels. http://www.digitaltutors.com/09/lesson_one.php?cid=3385

I thought if i take a high resolution picture the problem with the pixel data would be negligible.

[zber2]

Original by maxpd
@zber2: How did you the scurfs of your"dinocar" in your sketchbook?

[zber2]

Here is the alpha if you want to use it.

[system]

Thank you!

I tried another Gnomon Alpha. I find it really nice. But always the same problem. I think there isn’t any problem with the alphas. It is another problem. You see here the neck of the dino. It has 5 million polys.
I can smooth after using the stencil, but then also other nice details will be getting lost.

In your image i also see noise, but this seems to result from the alpha. Just like it should.

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[zber2]

original by maxpd:
In your image i also see noise, but this seems to result from the alpha. Just like it should.

Yes, I made this alpha myself and added noise to get some bumps.

[system]

But why these steps in my sculpting? My Polyframe looks nice, there is no shifting.

[zber2]

That does look like jpeg artifacts. I am assuming that that alpha from Gnomon is a jpeg. You can try Free Jpeg Enhancer to see if it helps.

edit: The best alphas will be 16 bit grayscale .psd file but 8 bit grayscale .psd work well too.

[system]

It’s a psd. A Freebie from there Website.

[system]

I increased the sub even more to 512 mil. polys. 5 mil. in this area. And the result is even worse.

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