Yeti tutorials

This first tutorial goes through the process of creating a fur and groom using peregrine labs Yeti plugin for Maya. I am describing step for step how to go about setting it all up.

In this second tutorial i explain how to make your fur system clump when you have a groom attatched.

I created a simple and straight to the point tutorial series on making a feathery wing.
Check out the details below:

wingCover_aToB_nonscaled

Basic walk through of a few nodes:

This tutorial goes through instancing and creating a feather coat:

This tutorial shows how you can set bounding objects to control of fur should grow or not:

This tutorial goes into controlling a groom through a texture map:

This tutorial goes through setting up your simulation:

This is how to export and import a groom in Yeti

This tutorial explains how to control your hair with a guide curve while animating the mesh.

This tutorial explains how to apply a texture map to a shader and then apply the shader to the yeti node “the fur”.
I also show the settings i usually play with when using V-Ray as my render engine.

This old tutorial was brought back due to a request, it shows how to cache your yeti simulation out.

For more Yeti tutorials have a look at Michael Cauchis page.
Michael explains in very nice detail how to both start a groom and how to manage clumping with Yeti.

 

 

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294 thoughts on “Yeti tutorials

    • Pepole don’t seem to have much demand for Mental Ray support, and apparently Maya doesn’t generate the caches to render with it, I was told that they had to bypass a lot of the API to get it to work for XGen.

  1. Hello, you GuidesTutorial .. the question …
    I think part of Python scripts … well … less security eaters go.
    I tried to write its own.

    import maya.cmds as cmds
    baseattr = 2.0
    for element in cmds.ls (sl = True):
    Attr = cmds.listRelatives (element, s = True)
    cmds.setAttr ((Attr [0] + *. outerRadius *), baseattr)

    I get an error of which …
    Please help me.

    • What error is it?

      Do you have the indentation right after the for sentence?
      IT should look like this:

      import maya.cmds as cmds

      baseattr = 4.0

      for element in cmds.ls(sl=True):
      attr = cmds.listRelatives(element, s=True)
      cmds.setAttr( (attr[0] + “.outerRadius”),baseattr)

  2. I have 2 problems with yeti!
    1. When i deforming the mesh , the furs are change their position on mesh.
    2. I cant render Yeti by Arnold kick(Export ASS and Kick). I copy Yetis Bin folder location to arnolds “Procedural Search Phat”, but it don’t working. How can i fix it?

    • Hi Kamran, you need to go to your render settings VRay Common and scroll to the buttom. There is the MEL/Python callbacks.
      You need to delete the pre render MEL and the post render MEL lines and it should work just fine again.

      Bjørn

  3. now when i load the yeti plugin it saye “could not create a PyNode for manipulator type pgYetiGroomManip” however the plugin works just fine but cannot render it please help ….. 😥

    • It still sounds like you have some text in your callbacks text that you haven’t deleted. Try to delete all text in your callback list, and maybe do a test scene in a new maya scene – just to see if you can render a simple groom.
      It’s hard to trouble shoot, because it’s a long time since I had errors like that. It’s a test of my memory. 🙂

  4. Hi there, Thanks a bunch for your awesome tutorial. If I may request, is there anyway you could provide a tutorial for instancing yeti feather (pgYetiFeather) with custom texture on each feather? Thanks again!

      • I have it on my current worksataion too right now, I just ignore it. I think it’s because I am not using Yeti, so the plugin is not loaded, but somehow maya still thinks that I want to use it. My work renders anyway. That is not the imediate reason why your fur doesnt’t render. But that being said I would maybe try to reinstall your Yeti software and see it that helps. Otherwise try to first contact yeti support, they usually respond within reasonable time.

    • There’s no such a thing bro, texture is only used to tell the yeti engine where to grow hairs. Feathers however are completely different thing, there’s no options to texture them (perhaps thru the Arnold shader, but it won’t make much difference anyway). You can attach only one yetionmesh node per object, and that’s where the shader is attached to, so only one shader per yeti node, sorry.
      If you attach two yetionmesh nodes, (it works with two separate graphs etc.) but when you hit render, Maya
      crashes so fast that that you start wondering, where you had it open in the first place.
      You can’t split the shaders in sets either, the shader which is in the Yeti graph is only for RenderMan, so if yo happen to have RenderMan, you are in luck, otherwise …scream at something (suggestion: technical support).
      So the bottom line is, if you’re ok with only one shader for your feather node, thats cool, or just use polygons with mapped texture.

      Awesome plug in, but it’s still very buggy.

  5. Thanks for the lessons, they are helpful.
    -Couple questions, using your guide curves tutorial, I can see that the groom (yellow curves) on your model are still sticking straight out and don’t seem to be affected by the guides the way the pgYetiMaya1 (black) curves are. I’m getting the same result, some hairs follow the guides, others stick straight out. Is there a solution to that?
    -Also, any tips on spreading the hair evenly for a fur coat? It’s for a furry coat that for a cartoony character.
    -Having to do with grooming, are there any ways to to keep the hairs at similar length when combing or changing the length? When increasing the length, I’ll get some hairs that aren’t affected so the effect looks like certain parts of the fur are chopped off.
    -Finally, for a character that is covered in fur, but has areas of shorter fur, like for the face and chest, and then areas of little or no fur, is the idea to create separate hair groups with multiple fur and groom nodes and just work in sections?
    Thanks for any feedback.

    • Hi Aamir,

      It’s hard for me to answer the first question of yours. It sounds like you need to adjust the area of influence for your curves, but I can’t tell for sure.
      I would just flod the mesh with strands and then change the radius of influence so that the coat is 100% covered.
      If you want an even groom you can always use the smooth attribute and then paint in the trouble area to make the groom even all around.
      I would generally try to keep it to one yeti fur node, but there is no stopping you in splitting it up and having more grooms and yeti nodes.

      I hope that helped a bit.

  6. Another question, is there anyway to control the fur length through a map? Any kind of gray scale map (based on UVs) to determine the hair length or where certain areas are bald. I’ve tried creating an attribute node in the yeti graph but haven’t had success. How would the same question apply for the texture as well.
    Thanks a lot.

    • Yes you can paint a black and white map to controll your groom or specific nodes in your groom tree, but you need to use a file node and connect it. It’s not something that I have made a tutorial on, but it should be straight forward.

      • Thanks for the replies, I’m trying to figure it out. I’ve tried adding an attribute in the groom list and then creating an attribute node in the yeti graph editor and then plugging a texture node into that which then goes into the grow node. I’ve also tried adding it under texture utilites > import texture and selecting my length map but that doesn’t work either.

  7. Hi, Bjorn, is there anyway to solve this: so i’m trying to cover bird’s body with let’s say 3 or 4 different types of feathers, is it possible to do this in one pass, with some random distribution of instances? or there is no way for multi instancing?

    • That’s a good question. I haven’t tried that. It should be possible, and as far a I know the new version of yeti has a feather node that might do the trick.

  8. I can’t render my feathers 😦 i use Mental Ray.

    jesus i worked too hard in my bird 😦 … greetings from Lima – Peru

  9. Hi there, how can I use a map in b/w for set up the length and amount of the groom? I’m not very good with Yeti, can you help me? can you make a tutorial where you explains it? thanx so much

    • It can be done and I would have to make a tutorial about it. I will see if I get the time. If i do I will make a tutorial about how to do that.
      In the meantime, I suggest that you just groom the fur length by orienting it in maya. It’s easier for beginner level tasks.

  10. Hi,
    I use feathers yeti, I create an import node with feathers that I connect to the instance node (with of course, another instance and scatter nodes).
    Everything went well up in the stage, but can not see the feathers in rendering and not in alpha?
    Do you have an idea?

    Thank you (and thank you for your tutos)

      • hello,

        I work in Vray, I think there is something I did not understand in order to have the rendering of feathers (hair and bodies work very well).
        My question was rather: How do you shading with feathers generated by Yeti?

        Thank you in advance,

  11. hi.. i have sim problem.. maya field (ex.air,turblence) with keyframe (translate,magnitude,,,,) do not working after several playback.(about 5-6 time) it cannot delete, move, delete keyframe, .. sorry.. poor english 🙂

    • It sounds really wierd that you can’t delete keyframes after playing your simulation a few times.
      As for simulations it is never a good idea to scrub through it if you aren’t running it through a cache.
      I am sorry, but I can’t imagine what the problem could be.

      • —– yans said that on : May 19, 2014 at 1:44 am
        hi.. i have sim problem.. maya field (ex.air,turblence) with keyframe (translate,magnitude,,,,) do not working after several playback.(about 5-6 time) it cannot delete, move, delete keyframe, .. sorry.. poor english 🙂

        I was asking this, because i have the same issue… any field on the scene for simulation crashes the scene, useless…

      • Hmm, is it keyframes on the groom or on the maya field?
        What exactly doesn’t work after five to six times?
        Make sure you add the airfield under fields in your groom.

      • If you just open the example scene in yeti “yeti_simulationWFieldsExample” , you can see the bug… when you play the sceen a couple times, it crashes… however noone noticed this problem 🙂

  12. Hi, Im using Maya 2013,Yeti 1.3.5 and Vray 2.4.
    i followed ur 1st tutorial to create yeti hair! and when i click Render there is “nothing”! expect Geometry! Cant render the Hair! please help what m doing wrong or the problem with the version m using?? 😦

  13. Hey can you share with us the actual resolution videos becoz I think youtube has compressed most of them and its difficult to see some of the options..

  14. Awesome thnx..
    Also , apart from the documentation that comes along Yeti.. is there a “Best Practices” documentation published by anyone regarding use of Yeti in a production Pipeline.

    • I havent come across any such documentation, you need to have a good pipeline mannager or just be really clean about your pipeline in general. Use Caches for both animation and fursim. I think it would be better to simulate fur on a cached out animation rather than in the animation scene. If you have the time of cause it would be cleaner and better to simulate and cache the fur out in a scene by itself in between animation and lighting.

      • Yeah thats the general norm while doing sim. Its must better to do it off cached animation.

        My question was more towards keeping the asset clean as with node based workflow, it could get really complicated with very complex noded based graphs.

  15. How can I change the ViewPort shading of the YetiNode. Right now from different angles, the fur strands look differently shaded.

    • But you shouldn’t be able to see the fur in the viewport? You must have a powerful gpu driven setup. Change the shader I guess? The glossy, reflective nature of hair makes light bounce off to a very high degree. Use linear workflow when you look dev and light.

  16. HI, I am tryin to render Yeti with a Vray Demo but I am not able to see the fur in the renders.
    I have set the following environment variables. Let me know if this is correct. I have using Maya2014

    VRAY_FOR_MAYA2012_PLUGINS_x64
    C:\Yeti1.3.5Maya2014\bin

    VRAY_PLUGINS_x64
    C:\Yeti1.3.5Maya2014\bin

    is there anything more than I need to do?

    • hi there , have you solve the problme of the vray to render yeti fur??
      i have the same problem with you,i really can not figure it out,

      • I am not sure what problem in particular? I don’t think I ever had a problem with V-Ray, if it didn’t render it was usually because there was a wierd MEl callback in the rendersettings. I just deleted those lines.

  17. Hi Bjorn,
    awsome tutorials! One Question:
    I have a groom driven by guide curves and a rigged character. how can I make the groom and the guide curves follow the deformation? I followed your tut on exporting groom nodes but had some strange results…

  18. Well, I don’t know exactly what I changed, but it works now..kind of.. strange thing is, if I check “lock to surface” on the curve set, the fur flow changes completely. any solution?

  19. Thx for your reply and your solution! Ithink it will definitely work but I found another solution within yeti.
    You can convert your guides to grooms with the mel command

    pgYetiConvertGuideSetToGroom( string $guide_set, string $mesh_object )

    That way you can do your major grooming for example in zbrush but still be able to tweak values an flow of the groom in maya 🙂

  20. Hey..
    How do you add some color variatons to the fur strands in the renders… like a a Hue/Saturation variation , so that each fur strands has a slightly different color variation from the other

    • Hi Rocky,
      I would plug a procedual texture map into the colour of your shader or something similar. There is no specific nodes to randomize texture at this point, and it’s not a reliable way to make something good.
      Bjørn

      • Adding color variations to the fur strands definitely helps to distinguish each fur strand from the other in renders.. especially if the character is far away from the camera..rather than it just looking like a big ball of fur with the same shade all over..
        You can try Shave and haircut’s “Hue/Value” Variation options or PFX hair also comes with Hue, Saturation variation attributes where in you can dial the amount of variation that are required.. it does make a difference to the overall render quality.. “)

  21. Did anybody managed to get it working with vray ? Still stuck, most difficult seem not to use Yeti, but to install it … Yeti’s working, but when I hit render with vray, no fur at all … Bjørn ? Anyone ? Please, becoming crazy not to succeed.

    • I had that problem at The Animation Workshop, then I complained to tech and later they had a new version of Yeti. It’s probably that V-Ray needs to know where the Yeti plug-in is installed. Try asking Yeti support on their email, they usually respond quickly.

  22. BTW, Thanks for the tutos Bjørn, clear, simple, great work, just can’t use what I learned cause of Vray …

  23. Using:
    maya 2014
    Yeti 1.3.5
    Arnold 0.25.0 ”
    But when i do Render ‘only Object is visible! no Hair! no error message!
    Need help!

    • You should tell Arnold where where to find yeti modules – Render Settings/System/ Procedural Search Path and you put your Yeti bin directory link there, for instance: “C:\Yeti1.3.5Maya2014\bin”
      Hope that works for you.

  24. hey Bjorn,
    really nice tuts, have a question for yeti collision. I have collision object shape in collision tab and collision is on also but the groom doesnt collide for some reason? I am not using width node is that the reason?

    Thanks.

    • Collide with itself? Self collission is very computing heavy, consider just using the damping feature to have the hair not go totally flat. If you have long hair though, it might be nesesary.

  25. Hi, Bjørn, maby you know haw can I use textures in Yeti GraphEditor, I cant understand yeti help “Texture file names can reference environment variables using the ${ENV} format as well as for different coordinate spaces.”

    Thanks

    • You may, but I can’t answer that. It changed over the time the tutorials were made, so I guess whatever version was the latest when the video was made is the one I used. 🙂

  26. Hi Bjørn,

    Thanks for al those great tutorials! They got me started right away with my Yeti 15day testdrive:)
    Maybe you can help me…. I’m using a set of guides for top of my characters mesh and another set for the hair in front of the face. Do I need to create 2 yeti nodes on my mesh or can I combine serveral guide sets on one Yeti node?

    Cheers,
    Marcus

  27. Hi, excellent tutorials pretty well describing how to best start. Quick question, any hint on how to make realistic grass ? Thanks !

    • Lots of reference! study how grass looks and then try to make the strands look like that. If you need a specific shape then you should use instances in stead of normal hair strands. Be careful with very broad strands as they act like sprites and will look that way when you render it in animation.

      • Thanks, it doesn’t seem that straightforward to do vegetation when it is with standard Maya tools. I am in the current process of trying out Yeti vs Shave&Haircut. Did you already go through such a comparaison and in such a case, what pros and cons did you see in them ? Cheers.

    • Yeti is good for big companies with their own tech department, it’s not very suitable for small companies or single users unfortunately. Shave and a haircut is getting a bit old. I would suggest you look into xgen for an alternative to yeti. We use xgen at Qvisten animation where I am at now.

      • Thanks. I am currently in contact with JoeAlter’s company and they seem to have a shifted lifecycle, which may give this ‘old’ image. Now, I couldn’t see any convincing XGen showreel, so I may have to give it a try.

  28. Hi Bjorn,

    I’m using curves generated from zBRush as guides with Yeti. This really works nicely!
    But now I want to add simulation to them. This is only possible with a groom attached to object..isn’t it? Problem then is that groom doesn’t seem to work with guides?!

    My workaround now is to use Maya’s nuclues system to make the used guide curves dynamic:) So the question is…Is it also possible with Yeti to use dynamic simulation and not using nucleus?

    Cheers,
    Marcus

    • Hi Marcus, sorry for the late reply.

      The best way to simulate your curves out of Zbrush seems to be by using the Maya dynamics. Your solution with the nuclues is probably the only way to do it as Yeti doens’t have it’s own solution for this at the moment.

      Bjørn

      • No worries for the late reply;)

        After doing some tests I’m skipping Yeti and going straight forward with my curves to the nHair option. Styling and grooming I’m doing in zBrush anyhow. Works really great and simulating collisions and so is much faster. Also had a look at xGen but I like the nHair option better. It’s more straight forward:) Trying to recreate Merida’s hair from Pixars Brave movie:)

  29. I have a question, perhaps you can answer, i have a small spider with a mere few hundreds of hairs. This is the first time i am trying to render a yeti animation, so perhaps it is normal – but still: for each frame rendered a yeti cache file is written into the yet/temp folder. this file is by each frame 1mb larger, so after 300 frames the folder it can easily fill my 30-40GB free space. can this caching be made more effective? or something?

    • Hi Andras,
      Ok my cache file is usually less than 1 mb and some even 0. 😛 But 300 frames of one mb should only be 300 mb?
      I don’t think you can optimize the cache file size without implementing some sort of comression in the process which is pretty hard to do even for a programmer. The cache file contains very little info so I dont think that you can compress it more than what it is. Best advice is to delete the old cache that you don’t need. 🙂

  30. Hi Bjorn,
    iam working on a bird model and used yeti to generate feathers , but when the count is more maya render is just collapsing . is there any solution to optimise this? its a major project and iam stuck over here hope u can help me.

    • Less feathers but bigger feathers?
      If it’s while the animation is running try to cache it out, or to cache out all your geo so you don’t have any rig or anything that can take computing power running in the background.

  31. What’s the right procedure to use Yeti fur on a model with blend shapes? My fur stays in its original position while it should update itself on the blended mesh…

  32. Hi,
    m using Arnold render (1.1.0),and installing Yet 1.3.10,
    i have to add MAYA_Module_path to Find Yeti plugin, but there is already have “Maya_Moudule_path for mtoa! .

    If i create for Yeti so the mtoa path automatically get replaced to Yeti! how to Add “Maya_Module_path” for Both!!??

    im new to Maya! Pls Help

    • Hi Manikandan,

      I believe that you can have both paths in the file.
      Unfortunately I used to have a tech department to take care of installations, so I don’t have much experience with maya path variables. I also asked Colin from Yeti central to make a installer for yeti, but user friendliness doesn’t seem to be a high priority for Peregrine labs right now.

  33. Hi, I am working on long hair rendering task and I would like to hear your suggestion of which 3D plug-in should I use? shave and a haircut , maya hair,or yeti?

    Thank you ,

    • Hi ShuiKwok,

      I am currently testing Xgen, and i will be able to give a proper comparisson soon. For now I would say Xgen is pretty good. Only use Yeti if you have a tech department to help with licences and such. If you are alone on a personal project I would reccomend Xgen.

      • Hi Bjorn, thanks for this comment & of course thx for ur tutorials here in this site.
        I feel that XGen is more complicated/difficult than Yeti . also i feel its not easy to achieve fluffy fur quality by XGen. I dont know,, What are ur latest thoughts about XGen for this matter ?
        Cheers

      • I think Yeti is easier to use, but harder to install. 🙂 if you have a tech department do deal with installation and maintenance, I would let the team use Yeti.
        Xgen is much more messy pipeline wise.

  34. Thanks a bunch for creating all those tutorials.
    Looks like you love Yeti Arnold combo,
    how do you control hair opacity?
    Arnold shaders opacity is not working when rendering Yeti hair hence there is no opaque flag to turn off..
    So how do you solve that to get nice light fur?
    Thanks 🙂

  35. I like the Feathers and Instancing tutorial very much,and I want to know how to shading and rendering the instanced objects,can you make a tutorial to explain that?
    Thank you!

  36. Hey Bjorn, Im trying to make a falcon, and I want to be able to texture the feathers created by yetifeathernode, Well, I cannot , all I can do is assign a shader to the YetiMaya node, but the problem with that is , In order to get different color feathers, Id have to have to use multiple maya nodes, and it still isn’t satisfying, Because, When I apply a texture to the shader, It applys it to ALL the feathers in total, What if I want to add for instance a striped texture that is mapped to EACH Yetifeathernode, Would you suggest a better way ? Any help would be greatly appreciated.

  37. Hi Bjorn, nice tutorials, helped me a lot. I was wondering, do you know if yeti supports multi tile textures, lets say I want to control the density or length on my hairs with a texture but I have two or three UV tiles on my input mesh. Is there a solution to this?

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