Advanced 3d Modeling and Texturing with Andrew Klein

Creating Height Map Alpahs in Photoshop from Color Maps:

One of the simplest ways to create an alpha masks to desaturate a color map. Once the color map has been generated and tested in maya, you can use it to create your
bump or displacement map in Zbrush. The target is a good 50% middle gray with white representing higher spots and black representing lower points. In the case above, the color map had a darker, muddier bottom which works easily when desaturated to create depth:

However, what if, the truck that made these hadn't run through muddy ground, but over sandy ground. The color texture at the "bottom" of the track would be lighter, and when we simply desaturate the map, this technique would produce the opposite result from what we intend:

At this point in time, I can use one of several solutions to "fix" the result.
a) I can invert the bump map
b) I can use an the Replace Color Adjustment, by eyedropping to select the color (or colors in case of the eyedropper+ icon at the top).
c) I can use the High Pass Filter and later adjust the contrast

To turn this bump map into a normal map, I can use either Crazybump or Photoshop.........

Creating Height Map Alphas in Photoshop from Color Maps:
The same process outlined above can also be used in the process of creating maps for skin or other organic creations. In this case, we look at the head.
Here is the head color map, created using the processes detailed in the week 3 notes.

From there, I desaturate, and use the techniques outlined above to create an alpha mask:

Using this mask, I will apply this information to the sculpt of my model
-I Create a mask from the alpha intensity. Do this by going Tool--> Masking --> Mask By Alpha, with Intensity and Blend set to 100

-You will also want to turn off your color channel to view the mask.

-Next you can start to inflate your model based on this alpha mask. Go to Tool-->Deformations--> Inflate. Or, Alternately, you can use the inflate brush, set to a very small Zadd value, and get more control over evert area of the surface.

-Turn off the mask (ViewMask): and you will see this change in your model:

This technique can be used on a variety of objects, such as this map, or piece of jewlery:

Specular maps are the maps you use to define a surface's shininess and highlight colour.
The higher the value of a pixel (from black to white), the shinier the surface will appear. Therefore, surfaces such as dry stone or cotton fabric would tend to have a very dark specular map, while surfaces like polished chrome or plastic would tend to have lighter specular maps.
The colour of a pixel is also used, to calculate the resulting colour of the surface. A very saturated specular map will have a very different visual effect than a grey specular map. If you need a more "neutral" highlight on a surface, your specular map should use the inverse of the diffuse map's colour. Using the same colour on the specular as on the diffuse will result in a more saturated highlight when viewed in the game.
You can use contrasts in specular to make a surface appear more visually interesting - for example, this door has a very dark specular for the wood while the metal parts are much lighter, which will make the metal stand out more as a shinier surface when light hits it. This sort of contrast can help make surfaces in the game appear more realistic too.

Mudbox also allows you to easily create Specual Maps right onto your model. Simply create a specular map channel instead of the diffuse map channel shown in the videos below:

Tileable Textures :

Using Maya or Zbrush, you can easliy bake model information to file texure:
Heres the technique for Maya:

Heres the technique for Zbrush:

USING xNormal to create normal maps:

USING Zbrush to GENERATE Tiling Textures:

CLICK ON THE IMAGE BELOW for a video of the process:

In my own version, I first created a rock from a simple polygon sphere.
Then I deformed it using the move elastic brush, planar trim, flatten, and clay brushes
Next, I added two layers of procedural surface noise to break it up.
I did this all on different 3d Layers so I could create and blend to make variable rocks.
I set my material to a gray mat cap, and created a polypaint with a spray stroke and a splatter alpha

From this rock I was able to snapshot it to a square 1024x1024 document (snapshot is Shift-s), rotating and moving the rock. I made sure not to touch the edges of the document. Once the I was ready to texture the edge areas with rocks, I left edit mode on my last rock and used the ~ key to pan/offset the document. From there I just kept snapshoting rocks until it was full up. This allowed me to create a full document.

I performed a Render on Best Quality, then exported the following image to be my color map:

Finally, I grabbed the NormalRGB material, set Zadd to off, and made sure I set MRGB to on and my color to White. I grabbed the Single Layer Brush (in the tool palette, its a 2d brush) and painted the whole document.
I turned off shadows in the render settings, and this gave me a matching normal map that I was able to also export for use in Maya:

Using Intermediate Models for projection purposes:

We can use these projection master techniques discussed in videos above to also create all sorts of surfaces, using temporary intermediate items to detail bigger surfaces. Here I create a few stones, cinderblocks and a quick piece of rebar, all from Zbruh primatives to project onto this turntable-base for the character show below. None of these meshes show up in the final model, so their topology is completely arbitrary. They exist only to deform the dome of the turntable in the normal map.

Zbrush 4.0 Tank Demo, click image below:

Techniques for Detailing Hard Surfaces in action.... The Vespa:

PreservingHardEdgesInZBrush from Nick Zuccarello on Vimeo.

A set of props can be thought of in many ways: a grouping of objects, parts of an arcitectural construction or facade, or in the case below, parts of a vehicle. This Vespa, shown below untextured, needed zbrush work on several distinct parts. Together, these elements make up but a small part of the overall vehicle. But detailing them in Zbrush, I was able to add a sense of realism to the project.

These chrome parts each needed just a little bit of detailing. An application of the logo applied with the inflate brush, and a dragrect stroke. The kickstart needed some grooves, whcih were applied with the standard square alpha and a line stroke in the projection master.

these refelctors uses a few more custome alphas, a tiling rectangle-shaped checker, and a line alpha which I made in photoshop. A screw alpha, downloaded from Pixologic's alpha library.
Circle and hoop standard alphas were used on the DOT reflector in the upper left corner. For the larger taillight (right side), a combination of the stripe and checker alphas were used, with a hand painted mask (standard brush + control key held) serving to isolate the application of the two areas. The checker was applied via Dragrect stroke for the small reflector (lower), and turned into a Stencil (Alpha--Make St) for the taillight, then brushed on with the inflate brush.

The seat (click on image below to see larger), was sculpted in 3 passes.
-First, the flatten brush, with a small brush mod was used to sculpt wrinkles in the fabric caused from the stretching-application of pulling the faux-leather over the foam and frame of the seat.
-Second, the Leather alpha, taken from a desaturated photo of the seat, was applied all over using the inflate brush, a spray stroke, and a radial fade (Alpha-RF) of about 15 to soften the edges of the brush. The alpha could also have been applied by turning it into a stencil.
-Finally, a custom stitch alpha was made and applied to the Stitch 1 stroke. With a large lazy-mouse smooth (and precision mode enabled on my Wacom Intuos 4 tablet), I was able to create the seams that come from the hand-sewn seat.

Then, it was on to the license plate (click on image below to see larger). The License plate here is 2 subtools, the plate and frame. A selecton of handmade, and photo generated alphas were applied as DragRect, and as Stencils.

The grips offered an interesting challenge of how to generate an offset circle pattern all the way around. To solve this, I created a 2 circle alpha in Photoshop. I then oriented the grip in the document so that it was more or less horizontal. Entering the Projection Master, I utilized the line1 stroke and the sinlgle layer brush with a Zsub of -25 to create these indentations in a horizontal line across the grip. I had to edit the stroke settings so that my spacing was just right. By trial and error, I arrived at a value of about 0.8. I drew these two rows at a time, picked up from the Projection Master, rotated the grip, dropped again, and repeated the process until the whole grip was detailed.

The tire was undoubtedly the most complicated (click on image below to see larger). I used all 3 techniques here.

- I first created a tiling tread texture in Photoshop, and laid it out along the UV coordinates of the tire using a UV snapshot from Maya. I imported this map as an alpha and masked from Alpha intensity (as seen in the lower left corner). I was then able to inflate using Tool-Deformations-Inflate to create a uniform inflation, that with zsub enabled, actually deflated the tread inwards, greating the grooves you see below.

-next I applied the "decals", created in photoshop and warp-transformed with the arc preset so they could be appled to the tire in Zbrush. I made this alpha into a stencil, and brushed through with the inflate brush to apply these details.

-Finally, I used a noise to spray onto the surface to give it a rubbery feel.

Zbrush Architectural Techniques:

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MAA 4435: Advanced 3d Modeling and Texturing The Purpose of this course is to introduce advance concepts for modeling and rendering through the combination of Maya, Photoshop and Zbrush. Focusing on various pipelines, this course covers concepts such as displacement mapping, normal mapping, Zspheres and their skinning processes, and 2.5 illustration.