I’m so confused and I never found a straight answer for this…
I know there are different kinds of hair systems, namely, hair cards, alembic hair and groom hair.
My concern is what is the best option for games in terms of runtime performance, particularly, big games with realistic looking characters.
Originally, I assumed hair cards were the best option as they are low polycount.
But having researched, I get mixed content of people giving tutorials of either of the systems and claiming that they are meant for games.
Now I am baffled.
What is the best hair system I can use for realistic characters for a game project?
OK so this is where we run into the chicken versus the egg problem of what would be considered the best options for a video game as practical use would have to be determine based on the type of game being made. For the purpose of our game of a retro type first person shooter performance is a must over quality is a must as well as other issues as to design intent as to the over all quality of the game.
For example designing the actors at the highest level of quality, ie metahuman, would raise the quality bar of the environment assets to a level to match the actor quality at the cost of performance.
On the other hand if the design is single player then you could afford to bias for quality so having a vision as to the desired end result requires sorting out your design path.
Cards: Typical use results in Anime hair styles. Not a bad result but dependent on the game style over realistic result.
Alembic: Is a type of file export/import that preserves point cache data so the result depends on the ability of the host application to create hair as to quality of result.
Groom: Cutting edge at the moment as the result is based on the use of splines to generate the rendered result. It’s not geometry as a base but rather uses the strands to define the shape which is then rendered as hair. At it’s root it’s a shader based rendered solution.
Geometry: Is middle of the road as to performance versus quality and in my opinion makes for an excellent trade off unless a photo realistic result is required. The Paragon characters make use of geometry that you can checkout and even use in the development of your own actors and since they are geometry could easily make use of LOD.
Materials: Material use on the other hand could add an unreasonable performance hit due to shader complexity.
So
The honest answer will come down to “It depends” and out actors took a few years of trial and error to achieve the look and feel but keep in mind there are different requirements based on purpose of design that goes beyond a 3d actor running and gunning that includes things like menus and cut scenes.
Sorry to say as with all game design questions not an easy question to answer with out the context of the bigger picture