I would like to know if there is a way to render out one displacement map that includes the details from many subtools in zbrush3.5
I have a model/tool that is uvmapped into one 0-1 uv space. It is separated into more than 40 subtools each divided 7 times with an average poly count of over 2 million for each subtool. (-all of this created great looking normal maps using zmapper in 3.1)
any help is much appreciated.
DD
Simple math says that this is impossible. Think about it:
A texture is made up of pixels. Each pixel represents a data point. You cannot have more data than the texture has pixels.
40 SubTools of 2 million polys each is equal to 80 million points. That means that a map must have 80 million pixels to hold that much data. Yet even the largest map that ZBrush can export (8192 x 8192) is only 67 million pixels, and that assumes that 100% of the texture space is used (something that never happens).
Even if you could create a map big enough to hold all that data, it would be a truly massive file size and animation packages would not appreciate you when you try to work with it. They handle smaller chunks of data much more efficiently because thos chunks can be moved around as needed. A single, massive chunk has zero flexibility and demands a ton of dedicated resources.
You would be much better off merging about 5-6 of your SubTools at a time and then creating 4096 x 4096 maps (about 12 million usable pixels) for your displacements. About 7 such maps will hold all of your data, and your animation package will appreciate you a whole lot more.
thanks for the reply, -so there is no shortcut to render from many subtools into one texture in 3.5. this would be nice to have as it could save time vs. rendering out separate textures and stitching them in photoshop.
as for the math, its good info and good rule of thumb.
In practice when rendering out normal maps, in order to get tiny details w/clean hard edges (stuff everyone likes to see on ornamental armor) more subdivisions are necessary even though most of the surface does not need the same density as the hard edged details. -so all I can say is that I can see a difference when it comes to normal maps.
I render out a 4k from lower subdiv levels (say 6 instead of 7) and the results look lower res. I’m less experienced with displacements.
-edit- this is game pipeline specific, so that is the one texture limit, Im looking into rendering out displacements of game assets for beauty shots. (in game a 2k from 4k texture antialiases the details well.)