I thought of creating this thread with hopefully a centralized simple guide for getting displacement from Zbrush into Houdini's Mantra. I've run around the googles, from thread to thread and forum to forum, because as you see below I was not getting good results due to some settings. Whoever will find themselves in this situation, maybe this thread will pop up among the first so they won't lose as much time as I did. Contribution in the form of correcting w/e is showed here or adding your own know-how, preferably with images, is highly encouraged.

I was getting the result you see on the left and even though I had read the help docs on that section it didn't occur to me to change the dicing method at first.



Unfortunately, Zbrush has some very cryptic settings into Preferences (among pretty much everything else) called FlipAndSwitch that have to be adjusted for various render engines. For Mantra, that number is 42. Douglas Adams, you were right all along.



And there are some settings on the geometry > render > dicing tab which seem to relate to optimization exclusively in the docs, but from my tests it has an impact on quality as well. There's the chance that I did something abnormal to make these settings have an influence on how the displacement render looks.




And for anyone interested to see my full experiment with displacement in Mantra.

Cool McNistor, I'm sure that will be appreciated. And I love those guys, very nice work.

Yea, thanks. I'm hoping the info in this thread will pile up, because I don't, by any means, live under the impression that what I did here is a comprehensive analysis on what goes into Mantra's dealing with geometry generation at render time, either from an optimization pov or a looks one. In order to get there, this thread will have to wait for me to become a Mantra expert or to have other users chip in with their knowledge and practical results.
I know the user base in general is not focused on this type of work, but I'm sure there a few out there and I'm hoping they'll take notice and respond.

Neat work.

I haven't spent much time with it yet, but newly released ZBrush 4R8 apparently offers some new vector displacement functionality. I'm sure you've taken a look already, but it will be interesting to see if anything has gotten easier from that end.

Bear in mind that vector displacement maps are not yet standardized within the industry. Each rendering engine approaches them in a different way, and can execute the various render steps in a different order. As a result, a map that works perfectly in one rendering engine will likely produce an inaccurate render in other engines. You will need to experiment to find the correct combination of color order and direction for your pipeline.

http://docs.pixologic.com/user-guide/3d-modeling/exporting-your-model/vector-displacement-maps/ [docs.pixologic.com]

Yes, new functionality regarding VD has been added, but it's related to working inside Zb, the export process of VDs seems to be the same.

What I like the most in R8 is the new gizmos feature. Long overdue, but it turned out pretty good: customizable, the rotate has angle snap with Shift and to top it all, they willingly or unwillingly, doesn't really matter, reproduced Softimage's behavior of moving the gizmo by simply holding Alt as a transient mode.

McNistor
Yea, thanks. I'm hoping the info in this thread will pile up, because I don't, by any means, live under the impression that what I did here is a comprehensive analysis on what goes into Mantra's dealing with geometry generation at render time, either from an optimization pov or a looks one. In order to get there, this thread will have to wait for me to become a Mantra expert or to have other users chip in with their knowledge and practical results.
I know the user base in general is not focused on this type of work, but I'm sure there a few out there and I'm hoping they'll take notice and respond.

Imho, generally you'll want to use render time subdivision, and better dicing quality if first option is not enough (both are under parameters of your geometry). That's, well, generally. Mantra seems to be using a sort of Renderman style, render time tessellation, so if mesh is not tessellated enough, it can't place the texture. That's how for example 3delight is working, but, while with 3delight plugin for Softimage, two or three parameters are enough for pleasant life (together with built-in automatic texture conversion), and error is just a blurred image - in Mantra, there are much more parameters able to do something wrong, object local and global render options. For example I'm not sure is there a way to get MIP mapping from external tifs, or there's always necessary to manually convert to RAT.

Not an answer, anyway somehow I got a habit to avoid any bitmap input in H, except environment texture. Good luck.

McNistor
I thought of creating this thread with hopefully a centralized simple guide for getting displacement from Zbrush into Houdini's Mantra. I've run around the googles, from thread to thread and forum to forum, because as you see below I was not getting good results due to some settings. Whoever will find themselves in this situation, maybe this thread will pop up among the first so they won't lose as much time as I did. Contribution in the form of correcting w/e is showed here or adding your own know-how, preferably with images, is highly encouraged.

I was getting the result you see on the left and even though I had read the help docs on that section it didn't occur to me to change the dicing method at first.



Unfortunately, Zbrush has some very cryptic settings into Preferences (among pretty much everything else) called FlipAndSwitch that have to be adjusted for various render engines. For Mantra, that number is 42. Douglas Adams, you were right all along.



And there are some settings on the geometry > render > dicing tab which seem to relate to optimization exclusively in the docs, but from my tests it has an impact on quality as well. There's the chance that I did something abnormal to make these settings have an influence on how the displacement render looks.




And for anyone interested to see my full experiment with displacement in Mantra.

McNistor
I thought of creating this thread with hopefully a centralized simple guide for getting displacement from Zbrush into Houdini's Mantra. I've run around the googles, from thread to thread and forum to forum, because as you see below I was not getting good results due to some settings. Whoever will find themselves in this situation, maybe this thread will pop up among the first so they won't lose as much time as I did. Contribution in the form of correcting w/e is showed here or adding your own know-how, preferably with images, is highly encouraged.

I was getting the result you see on the left and even though I had read the help docs on that section it didn't occur to me to change the dicing method at first.



Unfortunately, Zbrush has some very cryptic settings into Preferences (among pretty much everything else) called FlipAndSwitch that have to be adjusted for various render engines. For Mantra, that number is 42. Douglas Adams, you were right all along.



And there are some settings on the geometry > render > dicing tab which seem to relate to optimization exclusively in the docs, but from my tests it has an impact on quality as well. There's the chance that I did something abnormal to make these settings have an influence on how the displacement render looks.




And for anyone interested to see my full experiment with displacement in Mantra.

Hi McNistor,

thanks for sharing your information and your creature look really cool!

Can you please relink the images? I would love to try out these settings!

All the best
Christian

Hi Christian,
I no longer have those images but they were basically these two:

pay attention the the flip&switch settings in Zb prefs (42 for Mantra)


in Houdini, the shading quality and ray predicing seem to affect the most the displacement quality.


Hope it helps. If you acquire new insights during your experiments, feel free to contribute.
Cheers!