Hello All,
Now that Maxwell 2.01 supports true 32 bit displacement maps, has anyone found a way to get Zbrush displacement maps working properly?
Thanks,
F
Ok, I’ve figured out the number process.
Maxwell either doesn’t read properly Zbrush’s 32 bit maps, or does the math differently.
But I got her figured out.
First things first, your geometry must have soft edges. Furthermore it should be subdivided at least enough to account for profile curvature, otherwise you will have faceted silhouette and if you “smooth UVs” in your map creation, it won´t line up right. So depending on your base cage, divide once or twice, remembering to smooth UVs.
Your displacement offset (the 50% point) with Zbrush 3.5 32bit maps will be .74
This is what you could call the “alpha gain” in Maya. With Mental Ray in maya, it is just set to .500
Why .74? If you take a 32bit map generated from Zbrush, and sample the pixels in monitor space (8 or 16 bit mode, not 32) it’s a value of 74%.
So our mid point is solved. Maxwell knows where the grey value / surface origin is.
Now the height, or scale. Unfortunately this also works differently. It may be due to the built in scale numbers in Zbrush 3.5, or some other factor, but a height number is going to be unique for each surface.
How to find it?
Create and export your 32 bit displacement like normal, put it in your textures dir… then, just create on in the displacement pallet in Zbrush, lower res so it is faster.
Clone it then look at the alpha palate for the AD factor. Whatever that number is, move the decimal point two spots to the right, and you have your height number for Maxwell.
Took me a good 6 hours of twiddling, but I finally got her. Works bullet proof.
The body had an alpha depth of 0.0143, so that resulted in a height of 1.43 (scale of a 100, probably due to maya’s scale factor for scenes in centimeters).
The jaw had an alpha depth of 0.9189, so a height of 9.189.
Remember, “height” or elevation is a %. So 9% of the jaw is not such a big number compared to 1.43% of the body. The numbers seem strange at first, but work if you think about it.
Hope this helps.
Can anyone give me more step by step direction on how to use ZB displacement map inside Maxwell? It’s such a great renderer and it would be a shame not to use it together with ZB. I sent PM to fbonniwell but I think he’s not so active these days. So if anyone else has something smart to say on this issue please share it here. Thanks.
Hey buddy.
The tests that I did were with Zbrush 3.5, and an older version of Maxwell. As I’ve posted here and in another thread, the workflow was a little different than in other packages due to the way Maxwell interpreted the maps. I personally haven’t touched Maxwell since then, (and furthermore I’m on holidays overseas) so I personally can’t be of any help. I know ZB4 maps behave a little differently in certain renderers than 3.5 maps did… Maxwell may have also updated it’s displacement protocol…
Though if you get in the Maxwell forums, or contact their support department, they ought to be able to give you a hand.
Good luck!
Thanks for your reply. I’ll give it a try.
I am trying everything with the newwest maxwell release and it just doesn’t work. Can anyone who had any sucsess rendering displacement in Maxwell Maya plug in help? A more detailed instructions would be greatly appreciated. I can’t manage to get the displacement maps to work.