By Pablo Munoz Gomez If you think that the model is looking too “flat” for instance,
you can add a tiny bit of shading to define the volumes a bit more:
I prefer the flat look as it resembles more a comic style, but if you like the above image, all i did was create new white circle, assign some inner shadows and set it to multiply and save a new image:
I think we are getting very close to the particular style we are aiming for. All we did in this section was create an image in Photoshop to use with ZBrush as the MatCap image. This is very helpful to create those precise lines and separation of colors and to achieve the comic style look. However, this is not the most powerful process of this technique, the best part is to modify the attributes of the MatCap once we have a working image like the one we created.
We are now going to tweak our material and dig a bit deeper into the modifiers of the MatCap. At this point is good if you are around 70% happy with how the MatCap is looking. Switch back to ZBrush and make sure you have your recently created image loaded in the MatCap you are creating. Also, double check that all modifier sliders are set to default values.
Remember when I said that we can change the thickness of the outline? We can do that within ZBrush and without drawing a new image with a thicker border in Photoshop.
This is where we explore that method. I will show you what most modifiers do but not in a particular order, we’ll start with the ones that affect the “shape” of the colours:
Depth and Orientation.
You’ll notice that you have Depth A and Depth B (same goes for most attributes) and that is because you can individually change the way the Raised (A) and Recessed (B) areas look in your MatCap. What Depth does, is visually change the elevation of the surface in your model, basically it does the following without altering the geometry:
So let’s change the “outer line” so it cover a larger area in out Comic MatCap, by moving the Depth A to something like 1.5
I looks like the colors are being duplicated and overlapping, that is because the Depth B is still at 0.
There are a couple of ways to fix this, the easiest is just giving the same value to A and B unless you actually are going for this type of effect.
And the other way is to set the colour of B (at the bottom of the modifiers subpalette) to black and just increase the intensity of A.
A guide to: Zbrush Comic Style render!
By Pablo Munoz Gomez For now we’ll stick with the simpler way and give the
same value to A and B whenever we modify a slider. Set the Depth A and B to 1.5
If you use the same values but in the negative numbers, you should get the same effect with the colours upside down:
That might be useful if you want to invert the direction of the light or where the highlights are placed, but I rather not use negative values here and use the Orientation slider instead and you’ll get the same result. Before we move to the orientation slider I should remind you that if you want the opposite effect in the outline of your model, that is a thinner line, you just need to enter smaller values in the Depth sliders like 0.5:
Orientation A and B are basically a control that allow us to rotate the image of the MatCap and therefore the orientation of the light we set up in the image. Let’s say I want the little green highlight moved slightly from the top to the right, all I need to do is put in the orientation sliders a value of 45 (as in 45 degrees).
Now let’s say that I am not a 100% happy with the colours, rather that update the image in Photoshop, I can simple change the Hue of the image changing all the colours at the same time.
Find the Hue sliders in the modifiers subpalette and tweak it to your liking (it works in the same way as the Hue/Saturation adjustment in Photoshop:
In fact you can also modify the Saturation and the Intensity of the colour in the same way you would in photoshop. for the following image, I change the Saturation to 0.2 (also for A and B) and the Intensity A to 0.1.
Pretty cool huh? I think I’m happy with this MatCap, You can save the MatCap from the material palette and also save the texture with all the modifications we just did. To do that just click on “create MatCap texture” at the bottom of the modifiers subpalette, and that will save an image to the Texture palette, which you can then export as an image file.
I’ll finish up here because I think I have covered a fair chunk of information in this section. we’ll take a look at some of the other attributes in the next chapter as they become more relevant to the technique will be using next.
A guide to: Zbrush Comic Style render!
By Pablo Munoz Gomez MIXING SHADER AND MATCAP FOR COMIC STYLE
RENDER
I hope you are still with me! I have covered the basics, sort of… and now we’ll get into more advanced Material creation. I’ll try to avoid repeating some of the things I have already mentioned, so I’ll encourage you to double check the previous sections, in case you are not sure about something that I say in here.
In this section, we’ll be multiplying the power of a single MatCap by 4! as we’ll use a QhadShader to build our next comic Material. You will find that there are heaps of application for this technique but for this tutorial I’ll concentrate on generating a comic material that we can use with or without polypaint.
Lets begin by understanding the QuadShader and defining some terminology that I’ll be using quite a bit:
QHADSHADER is a material in ZBrush that has 4 inputs (S1, S2, S3 and S4). There is an in depth explanation about this, in my tutorial on Making a skin material for BPR, we don’t need to be that extensive here, but in case you want to know more you can get the skin tutorial.
THE 4 INPUTS in the QuadShader, are simple channels in which you can insert either a MatCap or another single shader. You can also use the Mixer to define how each one of this inputs or channels interact with each other affecting the overall look of the Material.
Now let’s define some terms:
SHADER: For this tutorial I’ll refer as shader as any Standard Material from Zbrush
MATCAP: We should be clear on this by now, but let’s say that any shader that is driven by an image is called a MatCap.
S1, S2, S3 AND S4 are shader inputs, but because they can be part of a QhadShader (which is a shader) it can be a bit messy to explain so we’ll just call them Channel 1, 2, 3 and 4.
MATERIAL: At the end of the day, a MatCap or a Shader or a QuadShader, is a material but for the illustrative purposes of this tutorial, I’ll call a Material to something made out of a combination of shaders and MatCaps.
I hope I’m not complicating things too much, I’m sure you’ll get the hang of all this once we start with the practical stuff.
The idea is to create a reusable shader that can easily
A guide to: Zbrush Comic Style render!
By Pablo Munoz Gomez These are all screenshots using the same Material but with
some small value changes:
Let’s get started!
First, we are going to create the basis of the Material using a shader. Go to the Material palette and select the SkinShade4, this is a very versatile shader and is great for what we want. This also is going to be channel 1 (first from left to right) in our comic material QuadShader, so start by copying the SkinShade4 into the first channel of the Comic Material, here is how:
With the SkinShade4
selected, under the modifiers subpalette, you have two buttons: “CopySH” and
“PasteSH”. click on CopySH to copy all the modifiers of the shader.
Now we need to find the QuadShader under the Standard Materials in the Materials palette.
Once you have selected it, you’ll see 4 channels under the modifiers subpalette, click the first one to select it (pressed or orange) and then use the
“PasteSH” button.
NOTE: The little dots on each channel, are to turn on and off the visibility of that channel. Empty circle means ON and filled dot means OFF.
Great, we have our base shader ready to start, but before we can see what it does or how it really looks on our model, we need to turn off all the other channels. The idea with this base shader is to:
1. Create the “first pass” or basic outline of our comic material
2. Remove all or most of the shading and 3. Create a few subtle dark contour lines.
Creating a quick shadeless material with a black outlines is not hard, we could simply use the technique from the previous section and just build a MatCap. However, the reason I want to use a shader like SkinShade4 is because it will give us the option to do some simple shading or speculars later on if we want.
Go ahead and turn the Ambient and the Specular sliders all the way down to 0. Doing this, will get rid of any ambient lighting and specular colour, leaving us with just the diffuse to tweak.
A guide to: Zbrush Comic Style render!
By Pablo Munoz Gomez At this point, I like to turn on the polypaint of the model
or simply select any colour other than black or white. The idea is that this shader should not affect the colour so that we can use it on any other model with any polypoint.
In other words we are creating a material for the
“linework”.
Now there are some Modifiers in this SkinShade4 that we don’t really want to have ON. Change Colorize diffuse, colorize specular, AnisotropicDiffuse and AnisotropicSpecular, switching all to 0. Also reduce High Dynamic Range to 1.
We end up with a very basic material that it’s basically controlled by the diffuse amount and the diffuse curve alone. We’ll leave the Diffuse slider to 100 but the Diffuse Curve is what does the magic trick. Play around with the curve but we are roughly looking for this shape:
With that curve shape, you should get something that looks like the image below, with some sharp and subtle black outlines but you can also see a bit of the volumes.
We can still see some shadows that help define the volumes, but those have nothing to do with the Material we are building. the shadows you can see are simply “Preview Shadows” and you can control them from the Render palette, under the Preview Shadows subpalette. I turned the DeepSahdow off and the ObjShadow to 0:
Cool, I think this is very exciting because we managed to create this with only one Modifier of a simple shader. Since we are using a shader and not a MatCap, this also means that we can affect the outlines or shadows just by changing the light position! wohooo! look at this:
Not only that, we can change the light colour, intensity and the ambient light to quickly modify our comic look. think about the possibilities! and we are only 25% done with our Comic Material.
A guide to: Zbrush Comic Style render!
By Pablo Munoz Gomez For our second channel (S2) we are going to use a
MatCap. You can use any MatCap because we will modify it anyway, but I think the FlatSketch01 is already pretty close to what we need. Following the process of
“CopySH” and “PasteSH” from the first shader, bring the FlatSketch01 into the second channel (S2) of our QhadShader material.
Turn off the first shader (S1) so that you can only see the contribution of the shader 2. The idea with this second shader is, to create the “volume lines” that describe the shapes and masses in your character. I’d say that the FlatSketch01 does a pretty good job but it can be further refined.
Start by turning the opacity to 100 to make sure we see what this shader does at a 100%.
We are going to tweak the Cavity Detection and Cavity Transition to create the lines based on the crevices, peaks or hard edges of our model. Let’s just do a quick overview of what these modifiers do:
CAVITY DETECTION: Essentially, this slider defines how strong or how much “contrast” there is between the raised areas and the crevices or cavities. For the purpose of what we are trying to achieve, its almost like using Levels in Photoshop to contrast the lines of a sketch.
As soon as you turn this slider ON (any value other than 0), you are enabling all the “B” sliders. I have already mentioned these in the last section when I talked about Depth A and B and Orientation so let’s just sum it up like this: If the Cavity Detection equals to 0, any “B” slider is irrelevant as it won’t have any affect.
CAVITY TRANSITION: This is obviously linked to the Cavity Detection slider, but it deals with how sharp or soft the transition is between the raised areas and the crevices. This modifier will greatly affect the look of the shader because it allows the input of either positive or negative values (This will also serve as an “invert” function for our purposes).
TIP: You can benefit from the “B” sliders without having to see the cavities. You can make the Cavity Detection = 1 (this enables the “B” sliders) and change the Cavity Transition to 0 (which keeps the “B” sliders ON but without seeing any cavities.
Hopefully that is not too confusing. Basically what we need to know about these sliders to create our comic material, is that the Cavity Detections will gives us lines in deep areas and that the Cavity Transition will determine the sharpness of those lines (also invert them).
Before we tweak those setting, change the colour B to black and leave the colour A in white. We are not going to use the Intensity A and B that are right below the Cavity Transition so change them to 0, instead we’ll use the Intensity A slider at 1, located towards the bottom of the Modifiers subpalette.
The difference is that the first two deal with the Texture input of the MatCap and the second two refer to the intensity of the colours we picked for A and B (this will make more sense in a few paragraphs).
A guide to: Zbrush Comic Style render!
By Pablo Munoz Gomez We also need to get rid of
the texture image used by the FlatSketch01 shader so select the texture input and then select “Texture Off”
from the quick pick popup.
Ok, all we need to do now, is set the Intensity A to 1 to get 100% of the A colour. Then you can play with the Cavity Detection and Cavity Transition sliders to to find a nice balance between A (White colour for the raised areas) and B (black colour for our cavities).
Here are some examples with their settings:
And the final values I end up using:
You don’t necessarily have to use the settings I used. Since you have a different model, the material will look slightly different than how it looks in the Kepler character. Either way you should aim for something that look a bit like this using the test head or test objects:
We basically want a good balance of white for the raised areas, close to pure black for the crevices (our volume lines) and gray as an in-between for all the flat or smooth areas.
At this point, this is as exciting as the ZBrush default sketch shaders could be, but there is a difference: We have set up the rest of the modifiers, to just add a couple of extra steps and watch the magic happens! Ready to be amazed by the power of ZBrush?
Turn the Intensity A to 3 (the first one right below Cavity Transition). Nothing happens… still no magic.
That is simply because as I mentioned before, this Intensity sliders are very important for a MatCap, but our shader right now, is not really a MatCap in that we haven’t added any Image.
Go ahead and click on the Texture input, and select the Texture 28 (the one that looks like white Marble).
YES!!!! THIS IS IT! this is what we are looking for but how?
A guide to: Zbrush Comic Style render!
By Pablo Munoz Gomez Well, once we add the texture we have an actual
MatCap again driven by the texture. The texture is replacing everything that we set up to be gray when we tweak the Cavity sliders. leaving the raise areas white and noticeable (colour A) and the cavities black (colour B) everything in between is governed by the texture.
This is super cool because ultimately, we can add any texture here, to create any type of MatCap, and we’ll retain the “Volume Lines”:
You might have noticed in the previous examples, that the colour information from the texture input is mixed with the Gray colour which makes the colours look dull.
This can be fixed by tweaking the intensity A, but we want the comic look so we won’t worry about that in this tutorial.
Cool, all we have left is turn ON our base shader (S1) and see how it looks.
OH WHAT! all the hard work gone!.... no, it is still there but we haven’t told ZBrush how to mix S1 with S2 so we are just getting both at the same time with the same contribution. All we need to do, is open up the Mixer subpalette to define how we want the Matcap in S2 to be mixed with the Base Shader in S1.
Make sure you are in the MatCap (S2) and open the Mixer.
TIP: you can shift+Click a subpalette to open it while keeping another one open.
I see the mixer as the blending modes of layers in photoshop but on steroids… Not only you can decide the blending mode for your material, but you can also assign where and how it is applied. It’s like having blending mode and masking all in one place.
We want to keep all the Volume Lines we achieve with the MatCap S2 but we want to also have the functionality of the Base Shader S1, that reacts to the light position and has nice sharp shadows. So go ahead and set the blending mode to Multiply in the Mixer, to keep all the dark values and render the white colour transparent.
Hummmm it doesn’t look quite right… you can see the
Hummmm it doesn’t look quite right… you can see the