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XYZRGB
11-04-2006, 10:57 PM
I'm having hell trying to get something as easy as displacement mapping from ZB into XSI.

I'm finding that when I follow the XSI-ZB-XSI Pipeline Pdf, I end up with a model that is flipped inside out. When I flip the normals, this fixes it, except that the model then looks like a balloon. ( over inflated. When I lower the displacement value it shrinks it but there is still no detail )
A user at the ZBcentral had the exact same problem, but fixed it by exporting as a 32 bit map. I tried this, but must have done it wrong.

I'm so confused.

I copy > pasted this from a post in the ZBrush forum here at CGTalk:

I looked over at ZBrush central.

Still clueless.

Apparently I'm the only fool on the planet, since everyone else has seemed to grasp the XSI - ZB - XSI thing.

BTW, tried flipping the map both in and out of ZB and XSI. Exported as both a 16 bit and 32 bit.

Talked to the guy at ZBrush tech support. He's a cool dude who actually seems to want to help you. ( no sarcasm ! )
He said it sounded like I was forgetting to import the mesh back into ZB when the displacement map is created.
I'm sure I missunderstood him.

From what I assume, you are supposed to import the .obj ( XSI sphere ) into ZB,
> subdivide the mesh
> detail it
> go down to level one sub-d level
> then ...this is the part I'm confused about ... you ..what ...hit ctrl-N, and import the original XSI sphere.obj back onto the canvas ?
> set the DPsubPix setting to around 2, the DPRes all the way up, make sure 'MODE' is turned on
> hit ' Create Disp Map '
> Now export it using the " DE Options " and have it set to " D32 " ..right ? or do I use the other buttons around it ?
Im asking because I had read recently that you no longer need to worry about the Alpha Depth Factor if you export as a 32 bit image.
Am I doing that part right ?
Have any of the settings changed in the DE Options ?

Then... still in ZB, export the model as an .Obj and exit ZB.

> Open XSI > File > Import Obj
> search for the file that you created ....... now.....are you supposed to use your original mesh from XSI, or the one that you just created from ZB ? ( And are you supposed to save over the original XSI .Obj when you export from ZB ... or name it something like Sphere 2.Obj ? )
Anyways ... import the mesh to XSI > go over to the " Displacement Options " tab
> search for the image created from ZB
> put 2.2 as the Alpha Depth Factor
> Now ... do I flip the image vertically or not ... because it is flipped in ZB when it is exported ?
> View Dependent Refinement .... should that be on ?
> Put ' 2' as the subdivision level and..hit OK

> to get a complete mess :shrug:
skuby
11-05-2006, 12:21 AM
It's a pain in the ass the first time believe me. I'll try my best to walk you through it.

1. Create base Mesh in XSI, then import to Zbrush and sculpt as desired.
2. Use GUvTiles mapping method unless you have a custom UVMap from XSI.
3. Pick a good resolution in Zbrush (not nessicarily lvl 1) then delete lower resolutions.
4. Set your desired Disp Map options and generate from current lowest level
5. Flip disp map and export it
6. Export current lowest level

7. Import obj, set your alpha depth factor, don't reflip, view dep ref if you like
8. Render, probably need to adjust the values on the interp_linear node of you're render tree/shader a bit as well as screw with the geometry aproximation but thats about it.

9. If you're results still crazy make a new simple scene and try these steps with just a sphere. Once you get a simple test scene working you'll be set.

I swear to God that getting displacement mapping to work in any program is like a ritual initiation. You have to do it 500 times while praying, the same way every time until miraculously you're allowed into the club and it starts working for no new reason whatsoever. Scary but thats been my experience, I really feel for you, gl.
mocaw
11-05-2006, 06:08 PM
5. Flip disp map and export it


I'm having the EXCACT same issue! Hah!

So do we use the DE exporter...with the same settings outlined in the zbrush pdf on XSI and zbrush, or do we go straight from Zbrush after the flip?
mocaw
11-05-2006, 06:53 PM
Maybe I'm doing something wrong...but it seems to be working! If I switch to a R32 map in the DE settings, and then after importing in XSI, take out the change range node and use the alpha depth settings from zbrush for my displacement length it all works!

No major artifacts so far...and very fast!

Edit- using the Mulidisplace 2 method works better for me- I learned more about it from a MAYA/zbrush tutorial. You basicly save it out as a 32bit tiff with the same settings, but do it all through the mulitdisplace. Then you only need to use 2.0 or 2.2 for ADF as some have stated here on cgtalk- MUCH easier and less guess work!
XYZRGB
11-06-2006, 11:37 PM
Thank you for posting skuby and mocaw.

I'll have to try this out tomorrow since it is now too late.

Thanks again !
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