Blog

Fix and reset your Mixamo avatar rig

10/9/2019

The Mission

Creating avatars is really fun, all that 3D modelling can be very fulfilling, I know.
But after the fun part, comes the technical one, rigging.
On this post we'll explain how to use Mixamo to rig your characters in no time, and also solutions for some troubles you'll find along the way.

Resources

Mixamo
MayaLT 2019 or your preferred 3D software

Rigging our character in Mixamo

Mixamo is an automatic rigging website tool that allows you to create quick humanoid for free.
As long their shapes are not complicated.

If you are already familiar with this tool you can skip to the next part.
To log in you can use your Google Account.

Mixamo

Upload your character

Once you are logged in, press Upload Character and then drag the FBX you want to rig.

Note that the FBX file preferably should be in a 2013 or earlier, to avoid errors from Mixamo.

Make sure to orient the model to have the front face looking forward.

Bone structure

After that it will ask you to indicate different parts of the body on top of the model.

You also can choose the Skeleton LOD according how many fingers of the hand do you want your character to be able to move.

For a VRChat avatar you want to use at least 3 Chain Fingers because is the minimum that the game needs to detect correctly all the basic movement of your hand.

If Mixamo doesn't detect 3 "fingers" it will create less chains and you will have issues later.
Once everything is placed correctly just click Next and the autorigger will do his work. If you are satisfied with the result, click Next again. Now you can see the character in different animations to ensure the quality of the rig.

Don't trust, test

Before downloading your character from Mixamo, we strongly encourage you to run the following animations to test if there is going to be any problem with the avatar beforehand. Some of these problems can be solved after downloading the rig, but others cannot.

Skinning test makes you character make really exaggerated poses. Perfect to see if there could be any skin problem beforehand.

Typing is really useful if you want to check if your avatar has all the fingers rigged, since it moves all the fingers individually you can see if there are any issues.

Download that avatar!

If everything looks alright to you, go ahead and press Download and choose T-Pose and fbx.

Remember to not have any animation loaded in right panel, this could modify the pose of our rigged character.

Having trouble yet?

Mixamo's automatic skinning and rigging can work. But more often than not, your characters will encounter different problems that only can be fixed manually using a 3D software.

What went wrong? What do I do? These are questions that I made myself while working on these characters and I hope I can answer them here. Not all models are the same. Some have special characteristics and you have to look out for those.

These next examples will help you to identify and fix problems that could happen.

Bone influences

At first glance, this Hot Dog boy looks normal. It is in T-pose and it's completely rigged and skinned. Yet, there are some problems that we need to look out to.

It wasn't until we tried it on VRChat that we saw the problem. As I said, we all lost valuable time for not checking the rig and skin.

Seriously, check what's given to you. Make sure everything is okay.

Mixamo places a shoulder bone between the Upper arm and the Spine 2 bone. This bone doesn't usually move around much, but Mixamo still puts influence, leaving some nasty results, like this one.

Lifting up 30º the right shoulder leaves us with an horrible looking deformation.

This is the kind of stuff we should be aware of. For this particular case, removing all the influence of the shoulder bone will be enough to lead to some better results.

Removing all the influence sometimes is not the best idea so you can also reduce the amount of influence the shoulder makes on that part of the body for different results.

In this pictures you can see how the bone influence should look for both cases.

Influence removed

Influence decreased

Visemes issues

One particularly annoying problem that I personally found while making visemes for the avatars with Maya LT, was that even when the character was in T pose, if I tried using the blend shapes, the model will return to its original pose before the rigging. You can check what I'm talking about on the gif below.

To fix this we'll reset our character rig.

First, we will duplicate our original character.

Now bind the new mesh to the bone chain we have.

If an error occurs, right click on the Outliner and uncheck the "Show DAG Objects Only".

Scroll down until you see bindPose1.
Delete that, and repeat the bind.

Select the old mesh, then the new one. Go to Skin > Copy Skin Weights.
You can delete the old mesh, since it has no use.

Now all the blend shapes will work perfectly!

Conclusion

Like any automatic tool, Mixamo is a great time cutter that provides an easy way to go with decent results, but problems can arise, we covered some of the most annoying ones and hopefully this blog post helped you somehow.

Post by:

Pedro @05predo

Pedro Solans was an intern and now junior animator working at Polygonal Mind's in-house team.
Animation film lover, Tekken player and animal huger .

Daniel @toxsam

Daniel García (aka Toxsam) is the founder and creative director at Polygonal Mind.
In love with videogames since he can remember, passionate about geometry,
VR addict and energetic persona.

Comments

How to optimise VRChat avatars for Quest

10/3/2019

Comments

Premise

Back in May Oculus quest was released, it is a standalone device that allows you to use VR without needing to use any PC or wires. Until then you needed a high end computer to run games or experiences on VR so developers and creators didn't had to reduce as much when creating content or avatars for VRChat.

The Mission

The Quest has proven to be a very successful headset so far so there're new Quest users on VRChat, we'll use our 100 Avatars to show you how we reduce and optimise our avatars so Quest users can use them in VRChat.

Resources

MayaLT
Zbrush
Photoshop
Mixamo
Unity (latest stable version)

Before starting

During 2018 Q4 Polygonal Mind's team made a challenge of making 100 characters in 100 days, you can check more about it here.
Me and my friend Alejandro Peño joined the studio as interns and were tasked with a project where we had to prepare, optimise and upload over 100 characters to VRChat for the Oculus Quest.
It was challenging workload but through consistent job, we were able to transform this characters into optimised avatars for VRChat.

Some characters have proven to be more difficult than others, so I will make sure to explain you what problems I faced when fixing non optimal characters and how I managed to solved them. Even though we used Maya in the studio, any of this knowledge is applicable to any 3D modelling software.

So I'll recap a series of problem I faced when setting them for VRChat.

Lets start optimizing

Initially most of the models weren't created with VRChat in mind, and even less with the Oculus Quest.

Thankfully, all the characters were already modeled and texturized, so we only had to rig and upload them.

Or that's what I thought...

VRChat team provided the following rules to follow when it comes for Quest avatars:

1024x1024 texture
Less than 5000 tris
Preferably only 1 material
Around 5 or 8 MB uncompressed

Step 1 - Reducing Textures

This might be the easiest of all steps.

All the characters used 2048x2048 textures. So we had to reduce them to the desirable size.
In Photoshop, we created a new project with 1024x1024 pixel resolution. And then we imported all textures. Once they were all in and adjusted to the box, we exported each layer as an independent PNG.

Since they already had the appropriated name, we had 100 textures ready to go.

Step 2 - Polycount reduction

Most of the models had the right poly count, but some others didn't.
Franky's head is a clear example, it had 12572 triangles.

It is tempting to use an automatic tool to reduce the polycount such as decimation, but we do NOT recommend this at any cost. It will likely destroy your edgeflow and also can destroy the shape of the model, also can break UV layouts, so please think it twice before using it.

Here are some rules we follow when it comes to reducing polygons:

Always keep the shape intact. In this case the head must keep being a head with it's rectangular silhouette. After deleting an edge, zoom out and rotate the model to check if everything keeps looking good.

Don't delete edges where there is a texture seam. This will cause the UV map to go bananas, and that can take a lot of time to get it fixed, and even then, the results can look really bad.

It's crucial to reduce trying to keep the same edgeflow that the model already has, deleting edge loops left and right without paying attention to the edgeloop will lead you to sub optimal results.

... wait... What if the maps seams are non optimal?

What can you do when there are map seams literally everywhere? That's what happened to the 50th character, Samuela.

As you can see on the left no matter what edge loop you tried to select, there was always a seam. We couldn't find a way to reduce the number of tris (7.5k) without having to re-do the texture again.

But, thankfully we learned a workaround for this model.

We duplicated the model, and started deleting edges without thinking too much about the seams or texture, since we were going to make a new UV layout once the model is reduced.

Once the poly count was around 4.5k, we made the new UVs. Now that's all done, we exported each separated part (eyes, hair, ponytail and hair) of both, the new and the old model.

Once in Zbrush with every mesh and the old texture imported, we took the old Samuela model, subdivided it and made the texture to be poly paint.

Beware, Zbrush applies color to the model's vertex, so you will need to subdivide your model until it reach a million of points so you can keep as much detail as possible of the texture.

Time for to project the high model polypaint into the new one by subdividing the number of polys of the new to match the old one and now simply project the old Samuela to the new one. Repeat this part for every subdivision you have until you get enough texture detail on the new model.

Note that projection might not be precise and you might have to improve the texture in Photoshop.

Adding mouth and eyes into an existing model for Visemes

This part is completely optional. But it really gives your characters life when they are in game.

VRChat allows you to add facial expressions to your avatars so we had to add a mouth and eyes for every character so we can make them blink and talk using blend shapes.

Some characters already had eyes and mouth, but others, like Manuela had them embed on the texture, so we had to create them.

For a quick turnaround what we did was:

Extrude the mouth inside to make a hole
Modify topology if needed
Adjust UVs maps to match the lips and the mouth's insides
Add some teeth and tongue to the insides
Please keep in mind the 5k tris limit.

Rig

For the rig, we used Mixamo. Mixamo is a web page that rigs and skins automatically given some variables like the position of the wrists, elbows, knees, chin and groin. For the most part, Mixamo did a pretty good job, specially for all the humanoid characters. But for the not-so-human, you had to edit the skin to have a great result. How to fix those is a topic for a different dayone .

We'll talk about this deeper in a future post.

Materials

Like many of you reading this we firstly uploaded the characters to VRChat thinking only for PC users so all the materials were left with the Unity's default shader, but Quest avatars requires a mobile diffuse shader, so we had to change them.

If you have followed a good naming convention, this will only take 1 minute. For example we add a mtl_ prefix to all our materials. In Unity type the material prefix to quickly select and change them all at once.

Conclusion

100 characters are a lot. But like I said earlier, with some structure and consistent work after 3 weeks, we made this happen. At Polygonal Mind, we use Notion.so to have all our projects and task organised.

With that being said There were a bunch of characters that needed little to no optimisation, but some others that needed almost a full rework. This stuff takes time. Especially if you count them by the hundreds.

I hope this guide helped you to optimise your avatar for Quest users, it was a challenging project for us, but the work pays off very quickly once you see players wearing them in game.

So sit back, put on some music, and start working. It's been really fun making these and the paid-off of seeing avatars you've been working on being used by other people is a great feeling.

Post by:

Pedro @05predo

Pedro Solans was an intern and now junior animator working at Polygonal Mind's in-house team.
Animation film lover, Tekken player and animal huger .

Daniel @toxsam

Daniel García (aka Toxsam) is the founder and creative director at Polygonal Mind.
In love with videogames since he can remember, passionate about geometry,
VR addict and energetic persona.

Comments

The challenge of making 100 Avatars in 100 days

6/6/2019

Comments

The Mission

Creating content on a daily basis and keeping the steady work for a long period of time is both daunting and exciting.
On this case study I'll explain how a silly summer idea evolved into a social media challenge and then into cool avatars that thousands of people are using in VR right now.

Resources

Zbrush
Unity
MayaLT
Camtasia

Mixamo
Notion
VRChat
LIV

The impact

Having the avatars being featured by VRChat.
Unity's social media account reposting our content during the challenge.
Increase of the followers both on Instagram and Twitter.

Idea Background

It all started back in September of 2018. I wanted to start investing time into develop new game art styles using Unity, I was not sure how to start but then I found about the 100 days drawing challenge by Amanda Oleander on her Instagram.
Her challenge and commitment inspired me so much that I did my own version of it by doing 100 characters, 1 character a day for 100 consecutive days.

The condition for me was to make an Instagram and Twitter post with a moving character every day, so I had to create a steady workflow that could work for all the days of the challenge.

The challenge process

To succeed on a challenge like this you should try to define a process, and try to follow through it everyday, this will help you focus and will slowly reduce the time you have to dedicate to the challenge overtime, since your brain will be learning and adapting to the tasks.
If you don't know how to set up a process, is okay, most of the times processes are the result of repetition, so just start, do it once, and then write down the steps you made to get to the final result, then the next day try to repeat them. Over time, the process takes shape, evolves and improves.
During the 100 days a lot of people asked us how we managed to make 1 per day so we'll be taking a general overview of the character creation process. Most of the characters follow this scheme.

- Conception

With the help if ZBrush and using Dynamesh we're able to quickly generate a "Shape Sketch" of our model without worrying too much about the final polycount.
The result of this doodling will serve as a good base to generate the final topology on top of it.

3d character model from different positions

I personally like using Zbrush Retopo with Zpheres, but you can use Maya, Blender, Topogun, or any other 3D software for doing retopo.
If the shape is easy , let's say a Square or a Circle, I just export it as a reference and I would make it in MayaLT.

- Fixing retopology with MayaLT

I found over time that doing retopo with Zpheres can generate issues, so instead of trying to fix those with Zbrush, I just keep the mistake and fix it later on with a 3D modelling tool such as MayaLT.

Most of the work at this point is trying to reduce and remove triangles, and fixing animation loops
Even if you did the retopo on another software, I recommend to rotate the model around and try to find any issues on the model before starting the UVs.

- UVs and Textures

To generate the UVs of a character, I like to make a planar projection of the model, then start making UV cuts on the most ideal zones.

Here you can see all cuts we made for the characters, almost every model follows somehow this pattern.

Once you have all the cuts done, you have to unfold the UVs

To create the texture, we like to use Adobe Color in the studio. Easily help us find color schemes that work for out characters.

- Rigging and Animation

In order to save time we used Mixamo both for rigging and animation.

Mixamo is an online free tool that allows you to automatically generate humanoid riggings and it also provides you with a gallery of pre-fix animations that you can use on your project.

This tool is being used a lot when it comes to quick prototyping, so it was a no-brainer to use it for a challenge like this one.

- Unity scene set up

Finally we got to the point where I wanted invest more time at. Unity. The hole point of this madness was to force myself to use Unity as a quick tool to develop new visual concepts and ideas for future projects.

Not gonna dig into every detail of what I did with Unity, but there are a couple of tools that helped me to save time and get great results during the 100 days.

Toony Colors Pro 2 by JMO

I just love using it, making a cool looking material with this shader is extremely easy.
What I usually tweak with materials are colors and shadows and I also like to play a bit with outlines.

You can find a link to this asset here.

Post Processing Stack by Unity Technologies

This asset allows you to quickly add different post processing effects to your game scene.

You can find a link to this asset here.

Trying materials and shaders with our alien

- Final steps

Once you have a cool looking scene is time to add music. Sometimes when looking for music I found myself changing the animations to fit with the sound.
You can find tons of royalties free music online.

Once you have a music, we used Camtasia to record the Unity scene and edit the final video.
Now that everything is done, is time to post it on Instagram and Twitter.

- BONUS: extra tips to iterate faster on a challenge like this one

There were some days that I used time tricks to cut time on different parts of the process so I could invest more time on others.

Keeping body parts, cloning and reusing them on different models, reduces a lot the iteration time.

On other type of models like the food and tools ones I duplicated the face, legs and arms so I had just to model the body part.

Uploading them to VRChat as avatars

Halfway through the challenge we came up with the idea of giving a second life to all the characters by transforming them into avatars for the Metaverse. They were all already rigged with Mixamo so we knew by experience that they could be used, at least in VRChat.

Months later I decided to give it a go to the avatar idea with the help of 2 interns in the studio.

VRchat promo image with Polygonal Mind's avatars

Initially we just wanted to give them simple rig and upload them into VRChat, but after a few days into the work, we got reach out by the VRChat team, they loved the variety of our characters, and they suggested us to give them some extra love, by adding visemes and optimising them for the new Oculus Quest release, this way they could be used by even more players.

So we improved them and created a VRChat World to gather them. I must admit that Investing some more time into adding visemes made the characters way more interesting and fun to use!

Here is a screenshot of our Notion.so board in the middle of the project.

There is a lot of documentation already about how to upload avatars into VRChat, so we wont be covering any of it on this post, but, we'll be releasing another blogpost with some tips for optimising avatars for Quest using MayaLT later on.

Next Steps for this project

As you can see in our roadmap for now our most closest goal is to keep uploading all the characters into VRChat with visemes, we're really close to have them all up and ready to use. At the same time we'll be improving the world too.

After this our next milestone is to tokenize this avatars using the blockchain, our final goal is to release all model files for free to download on our site, as "Open source avatars" so anyone can use our avatars in any virtual world platform or project they're developing.

During the time I was writing this post, the guys at LIV reached out to us to use the avatars for their platform, so you'll be able to use them for streaming Beat Saber soon.
If you have a VR platform or a project you might wanna use our characters at, feel free to reach out so you can have a test before we make the open source release.

Conclusion

What started to be just a fun challenge to explore ideas, has become a larger project that is gaining interest in the VR community. Having 100 characters inside a hard drive felt like I wasted a lot of time just for a few Instagram awareness, but repurposing them for VR has been one of the most interesting things we've ever done in the studio. Walking around VRChat and seeing people having fun with your work, is just amazing.

Frog takes a selfie into vrchat with our Hot Dog

If you want to see the characters during the challenge, you can check our Instagram and Twitter accounts.

Post by:

Daniel @toxsam

Daniel García (aka Toxsam) is the founder and creative director at Polygonal Mind.
In love with videogames since he can remember, passionate about geometry, VR addict and energetic persona.

Comments

Blog

Fix and reset your Mixamo avatar rig

Pedro @05predo

Daniel @toxsam

How to optimise VRChat avatars for Quest

Pedro @05predo

Daniel @toxsam

The challenge of making 100 Avatars in 100 days

The Mission

Resources

The impact

Idea Background

The challenge process

- Conception

- Fixing retopology with MayaLT

- UVs and Textures

- Rigging and Animation

- Unity scene set up

- Final steps

- BONUS: extra tips to iterate faster on a challenge like this one

Uploading them to VRChat as avatars

Next Steps for this project

Conclusion

Post by:

Daniel @toxsam

Archives

Categories

Subscribe to get some 💚 in your inbox once in a while.