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View Full Version : Simple Question on ZBRUSH Displacement Maps in messiah


vjholofx
02-23-2006, 08:59 PM
hey everyone,

i have a question that is simple. i have some displacement maps i made in zbrush for a character. how do i apply it in messiah. i took a look at the taron post on the neckling but i can not see how he is doing it from there... i just need to know where i can get to displacement controls.

also, at present is messiah doing sub polygon didplacement or should i just use my huge mesh and wait for it to render

in other words how fast is the program at rendering these didplacement type characters.

i hope to post some of my work after i get this thing to work. by the way i like messiahs renderer. it kicks mental ray in the booty simply because it is easy to use

Wegg
02-23-2006, 09:32 PM
Well you create a new material and apply that material to whatever surface you want. Once it is applied. . . create a new texture map node and a min-max node. Click on the texture map node and load up your image. Apply it using UVs and pick which UV you want it to be applied too. Then link the image's value into the "A" in on the min-max node. Then link the output "A" into the bump of the base node. Click on the Min-Max node. turn on A and adjust the values to your liking. With Zbrush I would assume it is -1 and 1. Click on the base node. Put a value in for bump. Usually something small like .1. Now go to the surface tab, click on the object and then click on the "Displacement" tab. Pick what kind of Displacement Type you want. I have had better luck with "Pre-Generated Polygons" than the default. Set the Max Displace to 1. (Personally I think this is a silly step and it should just be a checkbox) and then set your Sub Level. THIS IS WHERE YOU CAN CRASH MESSIAH REAL EASY. SAVE before you render. Start with a setting of around 5 and work your way up. Generally 12 -> 15 has worked for me.

Thats it. Hope that helps.

rush123
02-23-2006, 10:22 PM
Hey vjholofx,

Wegg forgot to mention that rather than using the min-max node, you can use the remap function in the expanded texture node for greater convenience.

R

vjholofx
02-23-2006, 10:43 PM
Thanks Wegg for the speedy reply. if the upgrade came that fast he he....

just loaded the models into xsi to see how they would look...took about 5 mins to load but i am happy..tried to apply texture and xsi crashed...we are talking about 5 million polygons

gave messiah a try and it says....error loading .obj file.

last questions: i will use ur method and see what i come up with. would it not be easier if they just had a button that said 'displacement'...maybe in the upgrade

can u tell me from ur expereience how fast or slow ispacement maps will render in messiah?

vjholofx
02-23-2006, 10:49 PM
remap function in the extended texture node. got it ...i think...i will try this also and see what the results are...

thanks rush!

one quick note: love the soft but it would be really be good if we could have some type of guide as to what all the expressions do...kida of like the little moving pictures they have in the docs...or am i missing sumthang

Wegg
02-23-2006, 11:43 PM
can u tell me from ur expereience how fast or slow ispacement maps will render in messiah?

I have not noticed a single ounce of speed loss from a displaced model vs. a non displaced model. It does however get a little un-stable when you start cranking up the settings AND. . . the little funky goemetry issues you see in the renderer if you don't have it high enough make things interesting because its tempting just to crank things up.

BTW I have loaded models up with over 5 million polygons before and Messiah didn't even flinch. Its odd that your model crashed. :-(

As for the docs. Your not really missing anything. A visual guide would be fantastic. But. . . it would also be a fantastic undertaking for whomever attempted to do it so. . . <shrug>

vjholofx
02-24-2006, 10:54 AM
absolutely does not work.

everytime i put the subdivision level higher than five messiah totally crashes. i am using an acer amd 64 bit laptop with ati card.

followed all the instructions above and when i render at sub d 5 i see nothing at all. try at 7 and the renderer goes all black and then after about 5 mins i get an error report.

it is a bit frustrating.

is there any address of this in the beta.

maybe will just work my geometry down and use as bumpmap. though that king of defeats the point.

rush123
02-24-2006, 02:00 PM
vjholofx,

I've found a tutorial done by Chris Reid;

http://flarenova.com/Msx/Zbrush2Messiah.pdf

Also a mail on the Yhaoo group which might help;

CHRIS REID
First I suggest testing messiah on a simple model that you understand and
can easily and quickly control. Then move up to a 200,000+ model. I wouldn't
recommend using meta-Nurbs with a model of that size, it will definitely
slow down in messiah, and probably wont even work in any other app(that has
meta-nurb-like functionality). If you want to try it, press "Tab" with the
object selected and it will be meta-nurbed. You can adjust the sub-levels in
the object property blocks.

The reason the belly moves is that the bones work off of distance and
proximity. So you need to place bones all over in the body where you want
them to hold areas and move others. I assure you that you will find messiahs
bones much better/quicker/and easier to use than LW.

When zbrush first came out (2.0 anyways) I did exactly what you are trying
to do with a super-hi-poly model. It worked just fine. I don't remember
having any problems loading obj's. I won't have any time to make a tutorial
for a week or two if my workload lightens, but I can give you this to try.

If you saved your ztl in zbrush, then go in and make it much more low poly,
say 3,000 - 8,000 polys. Then get the rigging working. Then in the file tab
under one of the blocks you can replace the object. Just replace the lowpoly
with a highpoly. Then do the final tweeks.

http://206.145.80.239/zbc/showthread.php?t=30394

Hopefully this helps unless its a hardware/OS problem.

R

Wegg
02-24-2006, 03:36 PM
I think you are confusing MetaNURBS Subdivision level (Animate->MetaNURBS->Sudivision Level) with the displacement's Sub Level. (Render -> Surfaces -> Displacement/Appearance -> Sub Level). Metanurbs probably don't ever need to go above 3. But the Displacement can go quite high. I actually have mine set at 35 right now.

vjholofx
03-01-2006, 08:31 PM
well i have tried it a few times more and no dice. i also tried just using a simple sphere to see what was up and no dice again. soooos i am attaching the scene and a picture of what i have in zbrush. it must be that i am missing something. wegg? someone? please let me know what i am doing wrong. right now i am doing a test render, is the problem ther i wonder.
here is the shot from zbrush;


this sucks. cgchannel upload says .fxs is an invalid file type. . how do i get the scene uploaded for folks to look at?


the project i am working on is coming along nicely using messiah and as i said before i am going to be posting some images(and hopefully some test animations) on monday or tuesday. it would be really cool to use the displacement instead of the real high end geometry cause i m slinging a whole lot of polygons.

be checking this thread every few minutes to see how to get .fxs up.

cheers

sorry for letting the thread hang...i had a job that had t get done and sleep was not in the program.

MoodyB
03-01-2006, 09:02 PM
Did you press tab to sub-d your mesh before you tried to render it ? Afaik, you have to do this with any object you want to displace, or M:S will sit for ages rendering apparently, then crash.

Also make sure you're always using ' pre-generated polygons ' in the displacement block, and keep in mind that if you replace your mesh with an updated one, M:S will turn off sub-d and reset the displacement settings / values back to the defaults

vjholofx
03-01-2006, 09:26 PM
thanks moody!!! that suggestion stopped my crashing. now i can put the sub level up to 30 with no crash.....when doing a displacement u must tab -sub d ur mesh...that n eeds to be n some documentation somewhere

the mesh still does not displace though... any advice on how i can get the scene up to let someone look at what i am doing.



cheers

Wegg
03-01-2006, 10:12 PM
Gah. . . Ok ok. . .

Just e-mail it to me. I'll have a look.

billy@eggington.net

MoodyB
03-01-2006, 10:34 PM
thanks moody!!! that suggestion stopped my crashing. now i can put the sub level up to 30 with no crash.....when doing a displacement u must tab -sub d ur mesh...that n eeds to be n some documentation somewhere



Glad it helped.

One thing to also keep in mind when working with displacements. From the few tests that I've done here with displacements, I like to keep an eye on the memory usage in Windoze's Task Manager. If you're getting close to 2gb+ peak memory usage ( performance tab, bottom left corner ) and still need more subdivisions, etc... save very frequently as M:S can get a bit flakey.

Wegg or others might have not had this issue too though, so don't take it as gospel ( it could just be my pc )

vjholofx
03-02-2006, 06:13 PM
i don thave enough email memory to email the map from zbrush to u wegg. i just post it here. thanks for the tutorial rush. i noticed one thing i am doing wrong. when i put the texure to the mini max node i was using the texture in stead of color. i corrected it but still no dice.

still trying

cheers

Wegg
03-02-2006, 06:50 PM
I got it working.

I don't know what the heck was going on with that default material you had . . . so I started from scratch with a new one.

I linked in the Texturemap's color into the Material's bump. In the Texture map node I clicked on the "Remap" checkbox and set it to -1 Min 1 Max. (This skips the need for the min-max node)

Then I had to Flip the UV on V because. . . your map is inverted to the way your UVs are layed out.

The "Max Displace" should always be set to 1 if you want displacement. This should be a toggle switch. You control the height of your displacement with the bump value in the base of the material you are making.

You had everything else right. Just some freaky deaky thing with that material. I always scrap the default ones that load up and start with a "Full Shading" material. The need for that will go away in the next version of Messiah but. . . seeing as it isn't out yet. . . its a good rule of thumb.

And. . . NEVER use .jpg for displacement. Always shoot for a floating point color format like .exr or somet of the fancier .tiffs. 8 bits per color channel just doesn't cut it. It will look lumpy as hell. LIke. . . this.

http://www.eggprops.com/%7Eeggington/Messiah/Lumpy.png

Hope that helps.

vjholofx
03-02-2006, 07:50 PM
eureka!!! wegg u rock!:scream: :beer:

u all rock!!!

the boot looks nasty though. i suspect that the whole morph target deal in zbrush is the culprit in this instance. if you look at the knee part it is distorting weird. notice in the comparison picture i posted earlier the kne has 2 round things on it. in weggs render and the one i just did these are distorted. i think it is the morph target switching that id doing it. i am going to switch
back and do the whole process to the other mesh and see what that looks like and see the results which i will post.

vjholofx
03-02-2006, 09:34 PM
all is working now...but...there is this weird distortion at the top of the boot.

i rendered out and got it a bit more crisp than wegg's render with the settings and tif format and all..but can anyone give a reason for the strange distortion of the boot at top. i did another map from zbrush and used the other mess with the same results.. top is distorting. very strange.

cheers

Wegg
03-02-2006, 09:38 PM
I don't have Z-Brush. Sorry. Do you have any other programs to test it with to see if it isn't just a Z-Brush specific problem?

vjholofx
03-02-2006, 11:22 PM
i will try it in cinema 4d and if i can get it working in xsi.

will post results tomorrow 'cause i gatta walk the dog and go to sleep. it is 12 30 here in europe and i am bushed. thanks for all the help

vjholofx
03-03-2006, 09:50 PM
hey all. here are my latest results:

i could not resist doing a GI render. inho this is the best GI i ever used and i have used a few. it blows xsi iout of the water just in terms of ease of use and the image quality.

anywho: i fixed the destortion by making the texture a GUVTiles in ZBrushand and turned on adaptive(scan mode) also i clicked the MODE button...i love these 2 programs but i could do a bit less with the constant detictive work:sad: this is the way we learn i suppose for now.

also ALWAYS sub d the mesh before u try and render or u will be waiting a long time for a crash.

the only thing is that now that the geometry is in line the texture seems to be slipping a bit. will play with it this weekend and then post the whole character.(s) given this softwares name u should get a kick outta this project.

Taron333
03-19-2006, 12:55 PM
Aha, the colormap is slipping, huh?! Well, that's an easy one to explain and to solve for you, but requires you to do things differently in ZBrush, which is actually the culprid on that problem!!!

Right now you were most likely painting your colors in Zbrush and probably on the divided and modified geometry, right?

Here's the problem:
When you model the details in Zbrush, Zbrush really pushes the polygons around. When you later create the displacement map it actually tries to project the details onto the lowres geometry. The projected geometry fell on other places of the uv-map then where the actual detailed geometry is at the time. If you try to paint color onto it, it will be on the wrong place! I would need to illustrate that to show you exactly what this means, but...

Here's what you need to do to solve it:
-Make a new tool with your lowres geometry,
-subdivide it how ever many times you had it before you took the displacement map,
-apply the displacement map to the subdivided geometry (use the number in the alpha depth factor of that map, press the "alp" button on the masking tab within the "tool"-menu, go down to the displacement section, enter the alpha depth factor into "intensity" and hit "apply displacement".
-now create a color texture and paint your colors. They will sit exactly right then.

Don't forget to either flip the textures in Zbrush along V or in messiah's texturemap node. But you already know that.

vjholofx
03-19-2006, 02:03 PM
whoa! where do u get the time. ur evrywhere at once!:eek:

that solves the colormap problem. however can u explain the suishing of the boot at the top. i asked u in the other thread to please tell us how u get ur displacements outof zbrush so perfectly. which options do u select?

thanks.

playing around with the new version looks promising. quite promising indeed.

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