1 Tutorials ZBrush Using Photoreference Dom Jan 30, 2011 10:15 pm
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In this section, we'll show how to paint a head using textures taken
from photographs. Some of the steps will be the same as in the previous
example, so we'll be referring you back to that at times.
[edit]
Loading and Capturing Textures
Of course, the first thing to do is to get some textures to use. To do this:
1. Load your photographic reference image using Texture:Import. It'll show up as a thumbnail in the texture palette.
2. Display the image in the canvas by pressing Texture:CropAndFill. This will actually resize the canvas to the size of the image, and then fill the canvas with the image.
3. Change the rendering mode to Render:Flat. This eliminates the shading effects from lighting, and gives you the clearest and brightest view of the reference image.
4. Use the Tool:MRGBZ Grabber tool (this is an icon under
the "Current Tool" dropdown menu, not a grey labeled button) to extract
specific portions of your photographic textures, as desired. To do
this, select the grabber tool, and then Shift-drag out a rectangle on
the canvas. The dragged area will be added to the texture palette (at
the full resolution of that area--it will not be scaled or cropped).
5. Repeat the above as many times as necessary, to capture all of the textures you want.
In preparation for the next steps:
6. Using Document:New Document, create a new, blank canvas, on which the polypainting will take place.
7. Reset the shading mode to Render:Preview.
[edit]
Using the Spray Brush for Painting Skin
The Stroke:Spray brush is a great brush for applying copies
of a texture over a surface, without the obvious visually repetitive
effect that would be seen with other methods, such as texture tiling.
Let's start off with painting the model's skin.
Of course, this is just an example of how to quickly paint realistic
texture over large areas of a model. There are many other ways this
could be done, and other techniques would be applicable to painting
details.
At any point, you can check to see the effects of the texturing without shading by pressing Render:Flat. This lets you see what the texture colors will be once they are unrolled into the final texture map.
Remember also that you can mask portions of the model's surface to prevent painting over masked areas.
[edit]
Using the Spray and DragRect Brush for Painting Hair
We can use the Spray brush with hair painting as well, to
quickly paint in hair without obvious repetition. However, since we are
painting a directionally non-uniform texture (hair has a visual flow),
another consideration applies.
When painting with texture, ZBrush maintains a connection
between the direction of the brush stroke and the orientation of the
texture. To put it another way, the orientation of the texture is not
independent of the direction of the brush stroke. If you paint a
woodgrain texture using vertical strokes, and then make a horizontal
stroke across that painting, the grain in the horizontal stroke will be
perpendicular to that from the previous strokes.
In particular, ZBrush orients the texture being painted so that
the texture's vertical axis aligns with the direction of the brush
stroke. For our hair painting, this means that to obtain the smoothest
and clearest hair painting, we should choose a hair texture patch
wherein the flow of the hair is close to vertical.
With that bit of explanation out of the way, let's proceed.
# For the smoothest strokes and hair flow, you might also want to activate the Lazy Mouse feature.
And that concludes the use of the Spray stroke to lay down the base of the hair.
Now we'll use the Stroke:DragRect stroke to add highlights to the hair. DragRect
is particularly useful when painting (or sculpting) with textures (or
alphas), because it allows precise placement, sizing, and orientation
of a texture, all with one stroke. In addition, since DragRect does not paint along a path, we aren't constrained in our selection of texture by the direction of hair flow in that texture.
And then simply continue using the above (or other!) techniques to finish the model.
A few parting notes:
Jump to: navigation, search
In this section, we'll show how to paint a head using textures taken
from photographs. Some of the steps will be the same as in the previous
example, so we'll be referring you back to that at times.
[edit]
Loading and Capturing Textures
Of course, the first thing to do is to get some textures to use. To do this:
1. Load your photographic reference image using Texture:Import. It'll show up as a thumbnail in the texture palette.
2. Display the image in the canvas by pressing Texture:CropAndFill. This will actually resize the canvas to the size of the image, and then fill the canvas with the image.
3. Change the rendering mode to Render:Flat. This eliminates the shading effects from lighting, and gives you the clearest and brightest view of the reference image.
4. Use the Tool:MRGBZ Grabber tool (this is an icon under
the "Current Tool" dropdown menu, not a grey labeled button) to extract
specific portions of your photographic textures, as desired. To do
this, select the grabber tool, and then Shift-drag out a rectangle on
the canvas. The dragged area will be added to the texture palette (at
the full resolution of that area--it will not be scaled or cropped).
5. Repeat the above as many times as necessary, to capture all of the textures you want.
In preparation for the next steps:
6. Using Document:New Document, create a new, blank canvas, on which the polypainting will take place.
7. Reset the shading mode to Render:Preview.
[edit]
Using the Spray Brush for Painting Skin
The Stroke:Spray brush is a great brush for applying copies
of a texture over a surface, without the obvious visually repetitive
effect that would be seen with other methods, such as texture tiling.
Let's start off with painting the model's skin.
- Follow the steps described in the previous example to set up
the head for painting; ensure displacement sculpting is off, set a base
color for the skin, etc.
- To ensure that the textures we are using are not applied to the model as a whole while we are trying to use them, press Tool:Texture:Disable UV. Note:
Disabling UVs has another major benefit. Without UVs, your model will
occupy significantly less memory space. This might provide increased
speed, or the ability to perform another level of subdivision, or both.
- Now choose a texture appropriate to the area of the model you
wish to paint. For example, to paint the chin, you might want to choose
a texture, taken from the photo reference, that shows unshaven stubble. - Choose Stroke:Spray and an appropriate brush size,
and paint the skin of the model. As mentioned before, the random nature
of this stroke will prevent repetitive texturing. In addition, the
smooth falloff provided by the alpha and brush falloff lets the edges
of the stroke blend smoothly with whatever other painting exists on the
surface of the model. - Continue, using different textures, until the base layer of the skin is done.
Of course, this is just an example of how to quickly paint realistic
texture over large areas of a model. There are many other ways this
could be done, and other techniques would be applicable to painting
details.
At any point, you can check to see the effects of the texturing without shading by pressing Render:Flat. This lets you see what the texture colors will be once they are unrolled into the final texture map.
Remember also that you can mask portions of the model's surface to prevent painting over masked areas.
[edit]
Using the Spray and DragRect Brush for Painting Hair
We can use the Spray brush with hair painting as well, to
quickly paint in hair without obvious repetition. However, since we are
painting a directionally non-uniform texture (hair has a visual flow),
another consideration applies.
When painting with texture, ZBrush maintains a connection
between the direction of the brush stroke and the orientation of the
texture. To put it another way, the orientation of the texture is not
independent of the direction of the brush stroke. If you paint a
woodgrain texture using vertical strokes, and then make a horizontal
stroke across that painting, the grain in the horizontal stroke will be
perpendicular to that from the previous strokes.
In particular, ZBrush orients the texture being painted so that
the texture's vertical axis aligns with the direction of the brush
stroke. For our hair painting, this means that to obtain the smoothest
and clearest hair painting, we should choose a hair texture patch
wherein the flow of the hair is close to vertical.
With that bit of explanation out of the way, let's proceed.
- Choose the Spray stroke, and select as the texture a patch of hair with the hair flow close to the vertical.
# For the smoothest strokes and hair flow, you might also want to activate the Lazy Mouse feature.
- Now paint in the hair, with your strokes going in the
direction of the hair flow. In addition to eliminating tiling effects,
the Spray stroke will also introduce some randomization into
the orientation of the applied textures, which results in better
blending between different strokes.
- Some of the randomization done by Spray is affected by
the orientation of the surface over which it is drawn. If you don't
like the effect, just paint over it until you get something you prefer.
And that concludes the use of the Spray stroke to lay down the base of the hair.
Now we'll use the Stroke:DragRect stroke to add highlights to the hair. DragRect
is particularly useful when painting (or sculpting) with textures (or
alphas), because it allows precise placement, sizing, and orientation
of a texture, all with one stroke. In addition, since DragRect does not paint along a path, we aren't constrained in our selection of texture by the direction of hair flow in that texture.
- Choose a texture to use when highlighting. In our example, we
chose one that was brownish, compared to the black of the base hair.
- Click on a point on the hair where you want the texture to be
centered, and then drag out from that point to size the texture, and
around that point to rotate the texture. Here is a DragRect
stroke applying a selected texture. Notice the rotation. The texture
can easily be aligned to match the existing hair flow, or put at an
angle to show different patches of hair crossing.
- Repeat in other locations or with other textures, as desired.
And then simply continue using the above (or other!) techniques to finish the model.
A few parting notes:
- You may want to capture overlapping areas of the
photoreference at different sizes. This lets you easily use large-area
textures with large brushes, and smaller areas with small brushes to
draw on top of larger areas, while maintaining a uniform scale for the
textures. - Don't forget about the vertical alignment of textures when used with directional brushes.
- You can paint with very detailed textures, but try to make
sure that the pixel count of the texture approximately matches the
polygon count of the area over which you are drawing. (And if your
computing resources permit, using higher polygon counts can never
hurt.)