From the Tips and Tricks document included with the upcoming expression sets. Apologies for the long winded ness, I wrote this so beginners could understand it without too much difficulty. :)
Just a few handy tips I've picked up when moving a character from Genesis 8 to Genesis 8.1
All of your G8 characters can be easily updated to 8.1 in just a few steps. This doesn't require any extra software or add-ons, but will require a few steps and a little patience depending on your render machine's power.
The first thing you'll have to do is pull up a fresh G8.1. For this example we'll use a Genesis 8 Female to Genesis 8.1 Female.
In your Figures library in Smart Content (People folder in Content Library), find the Genesis 8.1 Basic Female in the figure library under Genesis 8 Starter Essentials.
Once you have her in scene, pull up your custom character, or a pre-built G8 character from your library. For this example, we'll use Victoria 8 (not Victoria 8.1) since she's the most commonly owned character.
Make sure both characters are in the default "T" pose by selecting the characters, look at the base, look for the little "pose" symbol to the left, select it and click Restore Figure Pose.
Select Victoria 8 and at the top of your studio screen, go to File/Save As/Shaping Preset. Name this file "(character name)_Shape 8.1". Make sure "current frame only" is selected, and simply hit Accept.
Next (with Victoria 8 still selected) go back to the top of your studio screen, go to File/Save As/Material(s) Preset. Name this file "(character name)_Mats 8.1". Simply hit Accept. (this is a handy preset to keep even after the transfer is done to fix the character skin if you make a mistake when using other products ;) )
If you are moving a custom character that already has an outfit, hair, grafts etc., you can easily move those over too by selecting File/Save As/Wearable Preset (UN-SELECT eyelashes!) and hit Accept.
Now select your basic G8.1 Figure and apply these presets. You're done! (almost)
Tips:
Pretty much everything that works on Genesis 3 and Genesis 8 will work on your new Genesis 8.1 character. There are exceptions...
G8.1 does NOT use the same eyeLASH materials as G3/G8, therefore if you want more luscious lashes, you'll need to own a G8.1 specific character with an eyelash preset. Applying G3 or G8 lash materials to G8.1 lashes results in the lash maps running sideways, which looks pretty weird in your render. Victoria 8.1 comes with 2 different lash options, personally I use her long lash option on all characters, they look great!
Genesis BODY poses, meaning every bone but the facial bones, will apply to Genesis 8.1 with no issues, so all your old G8 pose sets are ready to use (minus expressions).
All clothing for G8 will work seamlessly on G8.1, and most G3 clothing works fine after using auto-fit. Some accessories that apply to the face may have issues, but I haven't encountered any hair issues (yet).
Genesis 8 Expressions do NOT, by default, apply to Genesis 8.1. Many expressions sliders have been removed, and the remaining sliders have been renamed. DAZ intention for expressions going forward is that they be built using the facial bones directly, with a little help from a basic set of sliders. While some expressions can be built easily with just the basic sliders, a much greater variety can be created by adding bone posing, or "Bone Enhance".
Posters on the official DAZ forums have noted that there is a workaround to "force" G8.1 to accept G8 expressions. The results can be mixed. I do not recommend using this workaround, but take that with a grain of salt since I'm an artist selling G8.1 expressions. ;)
What I CAN say with no reservation, is that expressions BUILT on G8.1, that take advantage of the new bone system, look MUCH better than the old dial only expressions. This was one of the main reasons for the 8.1 update, and if you're not using 8.1 native expressions, you may as well be using 8.0.
DAZ has moved the corrective morphs from the sliders, directly to the bones. This allows for a MUCH wider range of facial movement without breaking bone and/or slider limits. In the past, to get very extreme mouth and brow expressions, the artist had to go FAR beyond the limits of the expressions sliders, which would usually cause odd wrinkles and fold the facial mesh over itself. With 8.1, using individual bones gives a superior expression as the corrective morphs that keep the face mesh from folding over, are now attached directly to the bones. These bone based expressions also work MUCH better on highly stylized faces and result in much less distortion on those faces.
Be aware that a few specific facial morphs, most notably stylized morphs, break the closed eyelid appearance. One of the most extreme examples I encountered in testing was Sakura 8. She's super cute, but her eyelids are heavily morphed, which means when using "Blink" (the new slider for "Eyes Closed") her eyelids don't shut evenly. This is NOT an issue with G8.1 or the expression poses. This character never closed her eyes correctly, even in her default G8 version. Any character with heavily stylized eyes will have this issue to some degree. Inner or outer eyelids may not completely close, or eyelids may overlap on closing. For overlap, the simple fix is to just go to the Parameters tab, go to the "blink" slider and reduce it until the overlap is gone. For eyelids closing unevenly, it's easiest to use PowerPose to adjust the bones. G8.1 has a whopping 8 BONES per eye in her eyelids, making it pretty easy to shift the eyelids completely closed.
Overmorphed Teeth. They look wierd, you don't want that.
Sometimes you'll have a character that you move to G8.1 and suddenly the teeth are super crooked. This is because G8.1 has it's own "Mouth Realism" slider. When you apply the old G8 shape to G8.1, it carries over the G8 mouth realism slider, effectively stacking it twice. Simply remove the regular "Mouth Realism" slider to 0 and keep just the Mouth Realism 8.1 HD slider.
That's it for now! For more tips and tricks visit the official Renderotica Forums and ask! We're always happy to answer! :D
Cheers!
Thunder-3D