ZBrushCentral

GoZ to Modo- HELP! ;)

ZBrush Usage Questions
#1

Im having a problem with GoZ and how the mesh is rendering in Modo. I get a micro SubD/polygon pattern all over the mesh from the Disp texture, even in areas not sculpted.

Im working with a mesh (low, UVed, OBJ) created in Modo. I then use GoZ to open it in ZBrush and work on sculpted details. After sculpting ( HD sculpting), i created a texture form Polypaint, and a Displacement texture.(smooth UV on and Flip V on ) as directed in the GoZ -Modo tut video. Back in Modo the model shows up with with both the color and disp texture correct but there is a problem when rendering.
I get a micro SubD/polygon pattern all over the mesh from the Disp texture (i presume?) a sorta polygon pattern. not the sculpted details but the SubD/polygon details show in the render. The viewport it looks smooth and fine? i Cant seam to get it right? Does anyone know what Im doing wrong? here are pics of my settings, what im talking about. Please help me if you know of this problem, solution. Thanks! …Soon, I will post a link to the ZTL. and LXO files Zipped if one wants to open it and help me. BUPMY-PATTERN-.jpg

#2

Since I have had the same problem, I happen to know the solution…but you probably figured it out by now. You might try to up the displacement distance in the material of your object… It comes in at 500mm… a setting of 600 or a little less works… also depends on the size of your map…I tested this on a 2048 map… Also it cannot harm to delete the extra Basic Shader that comes in on top of your displacement texture and use the shader at the top of the render tree… Unless you need it to specify very special render settings…

Hope it will work.

#3

Thank you, I tried this. and it does make it smooth but, there are still poly pattern,on some parts of the mesh…Way better but, i wish it was all smooth…I;ll try to post another pic. …Thank you so much though! Should I up the mesh subd level, to 6 or 8? its at. Thanks so much! If anyone else has any suggestions it would help.

#4

You can also play with the smoothing and smoothing angle sliders in the material. That improves the displacement tremendously. And you can up the subdivision level, but it does not need to be that high (3-6 is good too). What I noticed is that the preview window renders that rasterized pattern off and on especially after you have moved the camera…sometimes you get a correct preview there…might be a software bug… But if you just do test renders with F9, you get more consistent results and you can see when and if the displacement has really worked.

#5

Ok, sounds great, I’ll try to play with the smoothing angle, and 3-6 as you mentioned. You’re the best for helping me , thank you!
I’ll post a few renders to show my results…

#6

here are some new renders. not looking so good. there seams to be some blow out, in the corner from the zbrush disp. layer. here i have it on and off. …also in the Geometry pallet all the settings like Divide are grayed out. I can step up and down with the slider but, not the buttons, do you know why?
Thank ya! new..jpg

#7

At this very moment I have a parallel struggle to yours to get things right while exporting my detail. I made all the beginners errors possible. So I am actually glad you come up with your renders and pointing it out so clearly so that I can testrun possible solutions on my own model. You should also try out Normal Maps. They might be easier to get right without all these unexpected displacement errors. Also check if your UV map does not have any overlaps. Usually that is the reason for blowouts and gaps in your render. In Modo you can see very clearly where the red overlapping areas are in the UVs when you hit tab and look at the unsmoothed/unsubdivided mesh. Correct it there and re-import the corrected version to zBrush. You should have the model open in zBrush when you hit the Goz button. It will automatically be replaced with the mesh with the improved UVs. And then use the bump strength and smoothing sliders in Modo. With me the Divide slider is usually greyed out when, without knowing it, I accidentally created a mask or have hidden a polygroup. You can clear all masks and also command+shift+click on the canvas to make sure everything is unhidden.

#8

Very Interesting, that is all we PC users can say, but help we can’t, maybe one day when we get GoZ…

#9

from what i can tell the divide button is not working because you used HD geometry divisions.
if you want to divide the model again you will need to clone it, beware though that will delete your HD geo on the cloned model.

#10

Oh I see, thanks Spaceboy412. and All that have replied. I do wish PC users will have the GoZ available soon, even though its not so smooth for me yet, it seams like a great tool…If anyone see this thread and has more info/ help please do. Thanks! B

#11

To fix the ‘pixelated map’ effect in modo, lower the Displacement Rate in the Render Settings (perhaps from 1.0 to 0.5).

Test it with small increments, because it increases poly count at render time and will need to be varied according to render size (because of speed and memory etc.).

This vid might help a bit: http://www.luxology.com/training/video.aspx?id=168Lux TV

#12

There are two settings that control the quality of the displacements, the Displacement Rate as MotleyPete suggest and the Minimum edge length.

In modo, anything named “rate” is a measurement in pixels. So the displacement rate sets the length of the micropolys in pixels. This, however, can be regulated using the “Minimum Edge Length” setting. Modo looks at an edge and if it’s longer than the Displacement Rate and longer than the Minimum Edge Length then it subdivides it. If the resulting edge is smaller than EITHER one of those, then the edge is left alone. So you could have a really small Subdivision Rate but still be getting faceting because the Minimum Edge Length won’t allow any more divisions. At that point, it will take some experimenting to figure out the balance between smoothness and geometry density at render time.

Also, keep in mind that what looks good at lower resolutions is probably overkill at higher resolutions, be prepared to run out of memory, especially using the 32 bit OS X version.

One more thing: Since the Subdivision Rate is a measure in pixels, a rate of 1.0 = 1 pixel per edge. Going smaller than 1.0 as MotleyPete suggested generally increased the amount of geometry created while having no visible result since the edges are smaller than can be rendered.

#13

Thank you all!! i think this advise will work only problem is Now, I cant see the mesh in Modo? I sculpted in Zbrush-hit GoZ and its seams to transfer over , I see the mesh icon, the textures but, no mesh in visible range? There is a small Z in the middle of the camera view, (attached) Is this something in ZBrush im doing wrong, the draw size? I even exported an OBJ and its not showing up?..
z?.jpg

#14

(you don’t have the GoZ scene selected, select the top scene in the item list) If ever your mesh is visible in the item list, but not the viewport, you could just be too zoomed out. Select the mesh item in the folder, and hit shift + A, which will auto fit the selection. This applies even if you just have one poly selected, it will fill your whole view. Having nothing selected is just like having everything selected. Just hitting A will auto fit all elements in the scene.

First off, make sure your base mesh is dense enough. In your early posts, it seems too low poly to accurately displace. I had major issues with displacement on a fish recently using GoZ > modo. The base mesh was 200 quads. Bumping it into the thousands helped greatly.

However, even on the fins of my mesh, which were obviously thin, the displacement was inaccurate. What was a great solution for me was deleting the lower subdivision levels in ZBrush until the base mesh was above 50,000 polys. modo can handle this just fine. Then I used a 4k normal map instead of a displacement. Because the base was so dense, it retained the silhouette quite well, and rendered like the ZBrush sculpt.

Another bonus was render time, which always matters. With just a basic environment and some spread angle on the directional light, I rendered a 2k x 3k image in under 50 seconds. The same thing with displacement took 17+ minutes.

Here’s the thread I posted pics at. Go through the pages and see if it helps:
http://www.zbrushcentral.com/showthread.php?t=72585&page=21&pp=15

In conclusion, it seems that displacement is not always accurate on certain parts of meshes, such as the very thin fins of my fish where it bloated. I just think it’s the nature of the beast. There’s always a work around though. A normal map was one in my case, and separating the fins as separate meshes may have been another.

Good luck figuring it out :+1:

#15

James everything you said is so helpful i know and cant wait to try it but, as i mentioned, my mesh OBJ is not visible in Modo? As you see in this new image, i do have the scene and mesh selected but, no polys or anything? i hit Shift-A and also A, nothing…there seams to be something existing on the mesh layer cuz, it is bold…? I even tried to assign a new material and nothing? this is bugging me out! I keep re-saving- exporting OBJ manually from ZBrush, also using Go Z, nothing happens., sometimes it just opens modo and doesn’t import anything, other times it imports but, there no polys visible? Nothing…its even take sa good amount of time to open but, theres nothing in there…so weird… ?.jpg

#16

Beautiful sculpt, I love it.

Shift A is specific to each viewport also (camera, opengl, preview, etc.)

Try to middle mouse click and lasso around the center of the perspective advanced open gl viewport in poly mode NOT item. This will select all polys if it’s far away. It should tell you in the bottom right how many polygons you have selected in yellow text. Even before lasso it should say “All Polygons” if there are any. If there is, then try Shift A again. If that’s not the ticket, have you just tried rebooting everything?

This is a weird one. I’ve rebooted before and magically fixed a GoZ connection before.

Some other ?s are how dense is the base mesh, and what res and type of uv are you using? You are supposed to GoZ from the lowest subdivision level after creating the uvs from the lowest level (I use puv tiles) and displacement/normal from the highest. Your mesh seems pretty dense in the screen shot where you say you GoZ to modo.

This mesh reminds me a lot of my fish fins, I hope it displaces well in the end. Keep truckin’ you’ll get it.

#17

Two things make me think you’re taking the wrong steps. One is, in your screenshot where you say you hit goz, the mesh is full res, and the displacement is turned off. You said it takes a long time to open, could be because modo cannot handle millions of polygons freely like the beast we all know as ZBrush. So try this order. Save out a new version first.

1- Close modo.
2- Go to a lower subdivision level with at least a few thousand polys, maybe more. Delete lower.
3- Go to tool>uv map
4- Delete uvs if you have them. Set it to 4096 (4k) and hit PUVTiles.
5- Go to the highest subdiv level.
6- Go to tool>displacement map with smoothuv highlighted
7- Create displacement
8- Go back to lowest subdiv level.
9- Hit GoZ and select modo.
10- In modo, hit tab to switch to subdivision surface mode to view the displacement.
11- Render, since displacement is inaccurate in preview.

Any luck???

If you do not have lower or low enough subdivision levels, try to reconstruct subdiv under tool>geometry.

#18

James, I cant thank you enough for your involvement and efforts and attention to helping me out. Unfort I tried the steps you mentioned and it by deleting my old UV, (painstakingly created in Modo, with loop/step selecting, Unwrapping, moving, vert by vert where overlapped) I did try all the steps you mentioned (PUTuv) and still the model doesn’t not show up!

i was able to select in the middle of the view port and it looked like the model is there but, so tiny that it un sizable. i even tried re-sizing to 1000% xyz, nothing happened…Its def a problem with the size. of the oBJ, cuz, its loading in (takes a min) …Im going to upload the model to so you can take a look at it if possible, or anyone on here. I am so disappointed cuz, I spent hours modeling it, UVing it (1-2 days at it, attempting to get cut up) then sculpting the details in ZBrush…I really feel this is an issue of size, or …also i noticed a while back in my earlier test with GoZ, i saw the High/ Low value of the disp texture said “nan” or something like this, i changed that to -4% 4% and it worked but, was bubbled out, to much disp…man im confused. I wont give up and Thank you for everything! I’ll post the model (OBJ, mtl,bmp, ZTL) next Picture 17.jpg

#19

This sounds like a scale issue upon export. This looks like all 76446 of your verts are placed perfectly at the origin of xyz. That isn’t good. It’s not that the model is small, it’s that you’ve collapsed all it’s verts into one point in space. How, dunno.

I’ll look into it a bit today, but I think you can check the exported scale of your model under something like tool>export. Make sure it is at 1. Also look in the tool>preview window. What does it look like? It should be fitting in there visibly, not too big or small.

I would also post this problem at the Luxology forums under product support.

Once you figure out this scale issue, you will likely be able to resort back to your version with the uvs you laid out in modo. Just be sure to save out a different version to preserve it.

Also, go ahead and check your GoZ>modo connection with a dummy object or the GoZ test sphere.

Good luck :+1:

#20

I meant to say lowest…highest is for when you create the texture from polypaint…