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Maya 6/MR/NormalMapping -yes another one :) help!! plz

ZBrush Usage Questions
#1

http://www.headus.com/au/samples/disp-norm/index.html

I’m using the Shader network from the above link *ripped it out of the supplied scene file) and using my own normal map generated from ZBrush.
But for some reason the Normal Map using this network is +'ve on one side but -'ve on the other side of the mesh

(negative bump on the Right side, positive bump on the left side.)

I Plugged a Clouds image map directly into the bump after deleting the shading network and that bumped everything just fine across the mesh.

So I assume the above link/technique doesn’t work with MR in Maya 6.0 ?

BTW My displacement map is working just fine across the whole mesh as well so I’m 99% sure it’s headus’ shading network, and whilst I have much love for someone that would take the time to make a network for the rest of us plebs to use, it’s not working for me :slight_smile:

Right to my question…
Are there any other Normal Mapping Shader networks out there for use with Maya 6.0/MRay that I anyone has a link for? I’ve spent ages browsing and the above link was the only thing I could find
Thanks in advance
Hkitch

Oh I just had a thought, I think his model was lined up +/- X not +/- Z I’ll check again but does this actually matter at all?

#2

Not all renderers use the same RGB to XYZ calculations. I don’t know what Mental Ray expects but you might try flipping the X (red) and Y(green) channels.

To flip the colors you should enable the relevant Preferences : ImportExport : NormalMapFlip switches. You then need to recalculate the normal map.

A little testing should reveal the flips needed. Don’t forget to report back which axis flips are needed;)

#3

k I’m working through the flips today, how ever I’m not sure this is gunna work because the normal map is bumping fine on leftside of the character but it’s inverted on the right side.
I even took this map into photoshop and mirrored it over to see if that would work but that didn’t help either.
THen I thought it might have been the UV maps but I put a bump across the whole character and that was working fine.
So I think I narrowed it down to the shader network in maya. If the flipping doesn’t fix it I will try to have a look through the shader and see if I can understand it :slight_smile: But I’m really not a maya shading guru per say when it comes to pluggin things into tangents and facing ratios etc :slight_smile:
HK
Will post soon re the Flips Thanks again for the reply

#4 
 But for some reason the Normal Map using this network is +'ve on one
   side but -'ve on the other side of the mesh.
   (negative bump on the Right side, positive bump on the left side.)

Oops, I did not read that carefully. Yes, you might want to check up on that shader network. Unfortunately I know nothing about Maya.

Flipping the normal map in photoshop will do nothing, unless you flip an individual RGB channel. Take a look at the picture Pixolator posted in this thread. It might help you visualize what to flip in the zbrush preferences. Remember, you need to recalculate the normal map. It is not enough to export the same normal map with the new preferences. Just checking;)

#5

heya,

note that in the headus example, the r and g are switched (so the r connects to the y coord. in the xyz node, and the g connects to the x). this was my stumbling block…

-s

#6

Current Progress
A Flipped XY normal map from ZBrush produces a MUCH nicer looking normal bump in Maya 6/MR render. How ever, instead of causing the LEFT <> RIGHT inversions I’m getting the Chest is inverted bump and the arm bumps are looking as they should. lol
Can anyone recommend a good drug to be taking while trying to figure all this out?

I assume no one else has managed to get Maya6.0/MR working with ZBrush normal maps yet either, as I’ve tried a TON of things now / combinations that are just not working yet…

off to keep trying
…

Trying the R - G thingy now…

#7

i’ve been getting a fair bit of success. yet to test out thoroughly, but the general process seems to work out (using the headus network). how close is the shape of your lo-poly mesh to your hi-poly? are there big differences?
-s

#8

k Guys;

Couple of screen shots (they always help)

First things first;
Model exported from maya low rez mesh. Imported to ZBrush, brushed muscles and exported the tool.
I have been loading this tool back in for the normal map because I wanted to use a higher division level for the normal map mid disp high normal
So I have already exported my displacement maps at like a res 3 or so and they’re working VERY nicely.
I import the tool, save morph at low res, go back to lvl 3 and subdivide to 5, then paint my rough crappy normal test stuff.
Drop back to the lowest res
no flipping for now
Tangent and Adaptive selected, res 4096, switch to the morph target and then generate the Normal map. I then FLIP the texture in Y in the texture section so that it is the right orientation for maya, and export to TIFF.
From there I batch convert the TIFF to an IFF, load the IFF into this shading network for MRay in Maya6.0
http://www.headus.com/au/samples/norm-MR/graph2.fig.html
And I have done as tol, flicked the R back to X and the G back to Y so they are not switched (I get the SAME results mind you without this flipping of channels)
Turn off all my displacement mapping deleting nodes etc
and THIS is the friggin result!
I can’t for the LIFE of me get anything other than this crap going on…
This is the Zbrush model with the crappy zbrush line

and now for the maya renderer using MR

Notice how the chest is negative and the arms are positive bumping… earlier I was getting this effect across the left and right sides… sigh
Edit
Oh yeah another thing to note is that when I plug the normal map directly into the shader normal camera, and then use the Highest Quality Rendering it looks EXACTLY the same too…
EDIT
Exporting the low res mesh from zbrush again and reimporting this into maya again doesn’t change anything either

#9

if you don’t use tangent space, then plugging the normalmap into the shader’s normalcamera should work, but only if you don’t change the transforms, or deformation of your model.

as for where the rgb plugs into the xyz, i’ve been following the headus network, which plugs the R INTO Y, and G INTO X. Don’t know if this could be your problem. what’s your uv map look like? if you generate an automatic map in zbrush, say using guv tiles, does that give you a nicer render?

also, if you export out the morphed lores, rather than the saved older one, and then generate your normalmap from this morph, does that also give you the same problems?

also, are you using some kind of ambient occlusion/dirtmap for your rendering? try just using a standard lighting setup, and see what happens.

here’s a progression - the first in zBrush, the second WITHOUT normalmapping in mental ray, the third WITH normal mapping.

redBall_zBrushToMaya_0_1.jpg

#10

if you don’t use tangent space, then plugging the normalmap into the shader’s normalcamera should work, but only if you don’t change the transforms, or deformation of your model.

Tried that yesterday and it didn’t help, I turned adaptive on late in the procress due to reading it somewhere to see if it would help with the problem but it didn’t change anything.

as for where the rgb plugs into the xyz, i’ve been following the headus network, which plugs the R INTO Y, and G INTO X

I followed your suggestion before I posted the images, and I’m still getting the same results.

also, are you using some kind of ambient occlusion/dirtmap for your rendering? try just using a standard lighting setup, and see what happens.

Just a GI_Joe lighting setup, lazy setup by me cause I’m working through the normal maps not lighting :). ALso get the same results without GI_Joe in the scene as well.

ZBrush with Maya 6.0 and MR :td:

#11

One thing that you are not specifying in your workflow: were the UV’s generated in ZBrush, or in Maya? Did you export the low res model from ZBrush to Maya, or did you just apply the map to the existing model in Maya?

#12

One thing that you are not specifying in your workflow: were the UV’s generated in ZBrush, or in Maya? Did you export the low res model from ZBrush to Maya, or did you just apply the map to the existing model in Maya?

Generated UV maps in Maya
Imported the mesh to ZBrush, made the Displacement maps and saved out the tool.
Loaded the tool in ZBrush again, dropped to lowest res, stored MT, upped res to lvl 5, applied details well the yucky big lines dropped to low res, switched to MT, generated Normal map, Flipped image vertically and exported for maya.
(Made sure the document was the same side and the tool was rotated and scaled to the document exactly the same so there were no pivot changes etc that I am aware of)
Note I have tried both exporting the Low Res Mesh from ZBrush, and importing that obj back into maya, and using the original exported mesh, and having applied normal map to either I get the same results.

I also want to stay away from having Zbrush generate the UV maps as we have 12 characters to build for this project and we will be using Photoshop for texturing as well.

Sorry if there are times I’m not making myself too clear, have tried literally dozens and dozens of combinations/tweeks/approaches now so I might be typing stuff out a little rushed / in a funny head space :slight_smile:

#13

Welp I fixed it

I will run it through another test, and then post EXACTLY what I did here…
Thanks all for you help :slight_smile:

#14

I don’t know Why Normal Map doesn’t run correctly on Maya…I Proceed on that way:

I model an object on Maya with Y up ( Rigth hand system ).
Export it as an OBJ to edit that mesh in Zbrush.
StoreMT and process to the normal map…and then see the effect on Maya High Quality Rendering on my Viewport. Arg…!!:cry: Dam…Normal Map doesn’t seems to work Correctly with a Directionnal Light.

For Info : I connect Normal mal RGB Color “File” to Normal Camera “Lambert”

So What I have to set on my preference window for Zbrush to Maya (RightHand System) and for later in other way Zbrush to DirectX (LeftHand System) :rolleyes: .

#15

I serachin for some good params, and I test all Normal Map Flip.

I notice that the Directionnal Light seems to have a - 90 ° deficit to have good light effect…

#16

Ok I have config my preference to iFlipY iFlipZ eFlipY & eFlipZ but when I generate my normal Map I discover back in Maya that the normal Map Texture of Zbrush Was Flipped on V…I dont understand…

Please let me learn a good Maya - Zbrush - Maya tutorial for Normal Map.

#17

All textures must be flipped vertically when importing into ZBrush or exporting from. This includes normal maps.

You can do this in ZBrush by pressing Texture>Flip V before exporting the normal map.

That’s all there is to it!

#18

Is anyone surprised at all that Alias hasn’t stepped up to the plate and wrote a shader that works in Maya software, Real-time and Mental Ray. (it would be really nice if a new spot was added in the shader attributes for normal maps as well. Imagine using a displacement map for larger shifts in model topology, a normal map for mid range topology shifts that really didn’t effect silhouette, and a bump map for finer detail.) It really sucks that Maya is falling behind these days. Built in Corrective blend shapes sure would be nice, but hey I can do a fluid simulation. (Fluid simulation is going to be the next big thing in character creation and animation for those of you that are out of the loop!!)

#19

headkitchen, please conclude this thread by telling us what you did to fix it! I also had your original problem with the leftside/rightside mirror, one was correct, the other inversed. So, I’m very curious what your steps were to resolve the problem! Please post! thanks.

#20

Personally, Flip Verticaly correct my problem. I do it before export my normal map from Zbrush…and prefer to control the result with my personnal test program in c++/D3D who use Pixel Shaders…:smiley:

Why alias don’t coorect is viewport shaders system to resolve realtime visualisation problem…?:td: trust me Zbrush Works well…Maya was not Mature at this time with N ormal Map. I hope a good shaders will be created by an interresting artist.:idea: