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GA 3324 : Character Modeling

This course covers advanced modeling techniques for building 3 dimensional characters. Students wil explore techniques of character modeling to include various approaches to figure construction.

 

  
     
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Week 8: Detailing using Alphas and Strokes, Displacement and Normal Maps in Maya and Zbrush

 

Alphas and Strokes:

  1. Different Strokes can produce different results as well (all the images below are with just the standard brush at the same Z Intensity):


  2. We can also use alpahs (grayscale jpg, bmp, or psd files) to add detail to the sculpt. The Alpha Palette provides a wealth of already created alphas. OR you can make your own by hitting the import button:



    Here I have made a scales alpha for use on the fish which I will import:



  3. We can control the Radial Fade of the alpha to soften the edge as I draw it out:

  4. You can detail with custom alphas which can be made simply in Photoshop as 8-bit jpgs. Here are
    some examples:

  5. The text on the t-shirt was created from an Alpha made in Photoshop and the Drag-Rectangle Stroke:

  6. The stiching on these shoes was also made from an alpha, and applied using the freehand stroke with lazy mouse enabled (watch the video below):


 

The Projection Master
Once in Zbrush, we can detail with several options. We have the ablity to "drop"
the model to the 2d canvas temporarily using the projection master. This feature allows
us to detail color, material, or deformation using color and alpha brushes.


Decide what type of change you wish to make, then press DROP NOW.

Decide what type of change you wish to make, then press DROP NOW.
You can then detail with any brush you wish, and the change will apply when you PICKUP
your model at the end. For deformation changes, make sure you are at a high enough
level of detail or what you paint won't "stick" when you pick up the model due to the lack
of polydata.


Alphas and Strokes
The last two columns at the left show even more ways that you can tap into ZBrush’s power. The Alpha palette controls grayscale images that can be used to create unique brush shapes. You can even create or import your own. The Stroke palette, as you might imagine, specifies the way that your stroke behaves from mouse click to mouse release. Use this to draw straight lines, strings of beads, simulate a paint brush, or even introduce chaos. 3D objects use the DragRectangle stroke by default, but you can use any of the other strokes for interesting effects.
CLICK HERE FOR MORE INFO ON THE Alpha palette
CLICK HERE FOR MORE INFO ON THE Stroke palette

Here are a few examples of details added with alphas and strokes in ZBrush 3 showing off use of alphas and strokes.
Click on the images for larger views.

 

 


Color Maps for a Character: Zbrush and Photoshop (ADVANCED):

 

Creating Normal Maps:



Transfer Maps in Maya
What If you require a low polycount on your model, but a lot of detail (ie, a a gaming enviornment)? Using a normal map, we can transfer data from the high poly sculpt to the low poly model so that everything but the low poly arm's silhouette will look like the high poly mesh. To do this we use the Transfer Maps function (formally called the Surface Sampler in Maya 7). I have duplicated the rigged low poly arm and moved it into the exact same space as the high poly arm. I have then frozen their transformations and deleted their histories (Note, do not do DELETE ALL BY TYPE as this will unbind your skin/skeleton in the scene as well). Also note that the duplicate low poly arm shares the same shader as the bound low poly arm, but that the high poly arm here has a different material applied. This is useful since our normal map can automatically apply itself to the assigned shader, meaning that we are attaching the map to the bound arm at the same time that we create it for the duplicate low poly arm.


I assign the low poly arm as the Target Mesh and the high poly (sculpted) arm as the Source Mesh. Choose Normal as your output map, and define its name and file format (TGA).

I will choose to connect the map to the already assigned shader (as mentioned earlier), I will set my map size, and set my sampling quality to it's highest setting. When done I will Bake the map (which will take a few minutes perhaps). You might also want to bump up your search envelope (shown above in the target mesh section), not too far, but a little bit, which will ensure that it is searching the correct regions on the high poly arm. Below on the right we see the normal map is created.


These next images show us how the Low Poly arm looks renderd with and without the normal map from both the front and back. Note how the arm is also posed easliy for this.

Click on the image below to learn how to Fix Normal Map Seams:

 

Using 3d Coat to retopologize surfaces:

 

 

More videos can be found at:
http://www.3d-coat.com/tutorial/retopology/

 

 

 

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