Introduction to Maya - Rendering in Arnold
This course will look at the fundamentals of rendering in Arnold. We'll go through the different light types available, cameras, shaders, Arnold's render settings and finally how to split an image into render passes (AOV's), before we then reassemble it i
# 31 08-04-2010 , 03:18 AM
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Thanks Dave

Hi Dave

Its ok, I manage to reduce my polygon count for that hi-res head (the black man head, the one I actually posted the image of). For the sake of sharing, here's how I did it :-

1. Select the head in object mode
2. Click Mesh-->Reduce
3. Maya complains there are no non-manifold geometry and asks me to cleanup the mesh first
4. I click Mesh --> Cleanup after selecting the mesh object
5. I click Mesh --> Reduce after selecting the mesh object

The mesh polygons are reduced.

This can be done a few times by the way.

NOTE - The face doesn't look as good as the hi-res one but I have to work within my PC limitations!


I UV-d a front and side photo of Sam Worthington / Chris O 'Donnell on to my mesh with Photoshop Liquify and got some weird results like Sam Worthington's been drinking too much or Chris just came out of a bar brawl. Then I realised that the head mesh dimensions has to exactly match the Sam and Chris photo (front and side). Which means I have to modify the black man head mesh a bit to fit Sam / Chris.

In one of the four views, there is a View menu and then Image Plane which allows me to put in the photo as a backdrop as I modify the mesh. How do I make the image plane smaller or make the mesh semi-transparent so I can see both layers just like in Photoshop (without using Layer Editor) ?

If I was good at ZBrush, it would be probably better for me to modify the mesh there.

The other option is to create a NURBS or Polygon plane and attach the front and side image there and scale it accordingly as I work on modifying the mesh to fit Sam's or Chris's photo dimensions.

Any pointers?


P.S >> For Question 1, can anyone else help ?

# 32 08-04-2010 , 08:42 PM
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Hi ezanih


I hope this is use full this is one of my first uvs that I created in photoshop following a tutorial (that the link is broken) You use a front photo and a side photo then conbine them in photoshop. For working with image planes in maya I get a front photo and side photo make the the same size in photoshop then create poly planes in maya the same ratio size.............hope this make sence........dave




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# 33 08-04-2010 , 08:45 PM
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sorry forgot


Edited by gster due to very large image.

Dave please keep the image sizes posted down to a useable size, unelss linking to a host.

# 34 09-04-2010 , 02:53 AM
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Thanks again Dave

Thanks again, Dave. That's a great UV you got there! Normally the eye meshes need to be separated if you want to do animation such as eye rolling and eye fluttering (teeth mesh needs to be separate also). But for stills its ok.

I did 2 things yesterday :-

1. Watched the Essentials tutorials for ZBrush in the Pixologic Video Tutorials column from start to finish

2. Played around with UV-ing Chris O Donnell's head in ZBrush and Maya and Photoshop for about an hour (I got kids too!)

I think I'm beginning to get a grasp of UV-ing somone's head.

I'm going to have to put in many more hours in order to be competent.

I used a ready head mesh and tried to modify it to match Chris's head. I used both Maya and ZBrush. I converted the head to OBJ and imported it into ZBrush as a Tool for finer sculpting.

I elongated the black man's head so I scaled in the Y-axis. Then I made the upper head rounder, beefed up the cheeks, reduce lips size especially upper lip and finally, made the nose sharper. The finer details were done in ZBrush especially using the Simple, Nudge, Pinch and Smooth and Flatten brushes. I turned on x-axis symmetry in ZBrush. I had lots of photo references of Chris O Donnell front face but very few side face references.

I then imported it back into Maya. I tried to make a cylindrical UV of the head to export to Photoshop but failed. It already had a default UV but when viewed in the UV Texture Editor, the head seems to be broken up into many pieces - not the usual smooth UV like the one you posted above. I have another head mesh which I successfully cylindrical UV-'d. Don't know what's the problem with this one.

My next study will be to try and use Master Projection and ZMapper in ZBrush to try to texture Chris O Donnel's face in ZBrush instead of Maya. I know Pixologic's AUV tiled mapping is pretty accurate with good, sharp results. I also want to UV a lot of heads and build up my UV hands-on hours. I also need to learn to model heads from scratch (you know, Extrude, Merge, Split Polygon, Proxy and all that). Wow...so many things to do using one incredible software application!

Hope to post more of my work later, Dave.

Dave, if you've done (or know of) any work on how to do great explosions in Maya, please could you share it. :-)

Many thanks
Ezani

# 35 10-04-2010 , 09:55 PM
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Hi ezanih
I did put a link on your thread to uvs check it out it does explain how to use uv projection to get the best results, you have to understand the work flow between maya and zbrush to get the best out of them, say you have a good low poly base mesh that only needs fine detail like skin porse what you do is first you create UVs in maya (at a later date you could use zbrush UVs) then export to zbrush, in zbrush you divide the mesh to level 6 then create the porses on the model you then move down to level 1 and create your bump map then export your mesh plus the bump map to maya, sorry have not create explosions but should be some thing free on the net.............hope you are well.........dave




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# 36 12-04-2010 , 03:57 AM
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Hi Dave

Hi Dave

How are you today?

I spent the weekend doing (or trying to do) UVs of head meshes (namely Chris O Donnell's head mesh). I realized I used the wrong UV mapping - it should be spherical mapping for the head (not cylindrical). Once I used spherical mapping, I got the standard UV head mesh used by everybody.

Thank you again for the Maya<-->ZBrush UV tut. I managed to access it successfully and saved a local copy on my hard disk for future ref :-)

You're right - for the moment I will avoid using Texture Master or Projection Master in ZBrush and try to do most things in Maya and Photoshop except probably the finer head sculpting.

I noticed from all the UV tuts I sent you earlier, most of the UV experts actually built up the head mesh from scratch using polygon modelling with a front and side photo. The tut called Creating Sheikh Zayed (the latest) is pretty good and the results pretty realistic.

The problem I'm having now is I'm not that experienced at poly-modelling and I'm using and existing head mesh which I'm trying to deform to match Chris O Donnell's head dimensions. It would probably be better to try to build a head mesh from scratch and I get to learn polymodelling in the process (chuckle) but I'm trying to save time. I'm doing the deforming in Maya and ZBrush from my weekend work, I just realized that the head mesh must be pretty accurate for the UV texture to fit properly.

I think my head mesh is not that accurate enough and I will be doing more shaping this week by referencing photos of Chris until I can get a good UV. One question to you Dave is how can I set up an Image Plane photo ref in ZBrush as can be done in Maya. Another question is how can I move just the eyes lower (literally) in ZBrush - do I use the Move or Transform brush ? The shaping of the nose is also quite difficult. Its a black man's nose and I'm trying to sharpen the nose as well as reduce the size of the nostrils.

At the same time if I get the color map accurate, I just need to make a grayscale monochrome image of the same graphic to make a bump map. Then I will be adding specular, transparency and occular maps. I will later add hair and eyebrow with Maya Hair or from Visor or from Fur.

I noticed that the once accurate photo of Chris becomes a stretched somewhat blurry UV of the head mesh with some significant loss of quality (pls see screenshots below). I have always observed this in UVs (which is why I tried to use the generic Maya procedural shades initially) and it is preventing CG artists from doing realistic human animation. I dunno..I was probably referring to Beowulf but Avatar is pretty realistic! But that UV from Sheikh Zayed is really pretty sharp and realistic.

I dunno..I'll be putting in more hours to this Chris O Donnell UV of mine.

Dave, about the explosions, and to share with you, its pretty hard to do good photorealistic explosions in Maya unless you move into the realm of Maya Fluids and photorealistic particle shaders. You will also need BlastCode (commercial). Also check out Overburn and the Visor fluid projects.

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# 37 13-04-2010 , 06:33 AM
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Got a question

One question Dave with regards to UV-ing a head mesh - if we have a baked cylindirically mapped UV layout of a human head mesh which has been exported from Maya's UV Texture Editor and we have a photo blueprint (front and side) of a human head and face in Photoshop, we normally manipulate the photo in Photoshop with Liquify filter. Is it also possible to manipulate the UV grid in Maya's UV Texture Editor to fit the photo instead? What would be the results to the rendered head ?

# 38 13-04-2010 , 07:05 AM
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You could but you can get problems with stretching and compression on those areas.

The whole point of UV mapping is to lay out the UV's into useable and constant sized tiles (representitive of the polygon size on the mesh) that you can easily parin on.


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# 39 13-04-2010 , 08:41 AM
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Of course

Of course! Duh...you hit the nail on the head gster123. What was I thinking. Thanks a lot for that input, gster!!! :-)


Ezani

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