How to "Share" Topology

Community Community & Industry Discussion
1

Hey guys,

So I was reading up on the Order 1886 talking about their topology and UVs in their game and then they said…

"Note that our two main characters’ male and female head topology and uvs are indentical.

Shared topology is only useful if it matches anatomy as well, so we this reference texture called the ‘Anatomy Map’ that was used to make sure the key features on the face were aligned to the same edge loops across all heads."

Woah woah woah- hold on, how are you going to just skip right past that like you didnt say anything…

How does one “share topology?” If thats the case then retopo wouldnt be a necessity anymore and that would be amazing!

Btw I took a screenshot of the picture, here it is

http://img.techpowerup.org/170108/2017-01-07-22h14-32.jpg

2

I believe he is just referring to the fact that they have the same topology because they have similar anatomy and not that they physically used topology on one model and put it on the other.

4

Actually, it means that they do reuse a mesh so that they have the same topologly. They might start out with a base mesh with a topology that they like, and then they would sculpt it into each face they want to use using Zbrush.
Another thing that’s done is if you have a head already created (like maybe a 3D scanned head) then you can take your topology mesh and reposition it a bit on the head and conform it and reproject the details to it.
Most places do this type of thing and have been for quite some time, it helps immensely to have a standard for meshes.

5

It’s pretty straight forward to “shrink wrap” one low poly model to the high poly of a different model. Different tools might have different names for it.

6

Wait a second, how far off can the sculpted or scanned head be from the base nicely retopoed mesh, to do a reproject like so?

7

We use the same technique and it’s rather simple.

You start with a base character rigged and mapped and then use Zbrush to reshape the base form and the result is used as a morph injector. Nothing new and has been around forever being used by apps like Poser and Daz Studio.

8

This is mainly used for NPCs right?
Because if this was used with main characters who all have the same rig, they would look awfully similar when the camera is on them a decent amt of the time?

By the way how is the rig transferred over with this method?

The moment we bring a obj back into ZBrush the rig is gone?

9

Sharing rigs is pretty much universally done in games, and sharing fairly dense topology isn’t going to make characters look too similar.

For production, you don’t want animators having to switch rigs all the time you want them using the same rig they are used to, and you don’t want the riggers creating unique rigs for every character.

10

Nope topology sharing has been going on for years and was even used in the movie “Spirits Within” and of course “Lord of the Rings” by Weta for their Massive crowd simulator for the battle shots.

Well compare this

to this

Same base model same UV mapping bolted to the same rig I think someone would be hard pressed to find whats the same. :wink:

Well the first rule to follow is you can not change the vert count as exported to Zbrush but once done we bring the model back into 3ds Max, add a morph modifier to the stack under the skin modifier, and add the reshaped model as a target and set the target value to 100%. Once done we collapse the stack up to the morpher which bakes the shape into the base mesh and tada new character using the same frame work.

The thing is studio grade technology is years ahead of the game development curve and for the most part making it’s way in now because Unreal 4 does not hard code limitations like 64k mesh limits and 1k texture resolutions. Not it’s new impressive but seeing big boy toys actually work in whats called a game engine is. Makes me wounder if we will see a version of Massive for Unreal 4 as I hear Epic is working with Weta. :wink:

11

Yep, thats nothing new, in big productions everyone does that. Its called efficient pipeline. Or, well… the base for one.

For example when I was working on Disneys Cinderella we had to transform mice into horses, now guess what, mouse and horse models shared the exact same topology so we could seamlessly blend from mouse to horse rig using an intermediate blending rig.
Thats a different use but same technique. Just shows you how different you can make things look that have the same topology. Obviously that has big requirements on the topology, it needs to be anatomical, like the image you have shown. If those things are right, and the density is too, you could literally use the same topology for little kid as for a giant ogre or a monkey (save a tail).

From there, transferring rig information is easy. Topology is the same so you can save index based weightmaps for deformers and simply reapply them on the new build. You could go even further and automate 100% of the rigging process by basing joint positions off the anatomical topology features (this would require the modelers to know what they are doing tho… not easy).

12

Okay guys so for a real live example…
Im now up to the Retopology step.

On the left is my base model which I will use fro future children characters as well.
On the right is my completed character A.

http://img.techpowerup.org/170108/2017-01-08-15h51-54.jpg

**1) So should I be doing the retopo on the Base model left?

  1. What steps would I take after doing the retopo on the base model?**

-Im going to do Retopo with Quad Draw from Maya 2017)
-UV also done in Maya)
**
3) -Im planning on use Shape Editor from Maya 2016Ext.2-2017 for the rigging process Will this be able to be exported to antoher char?**

13
  1. You should make a copy of the base model, as that will be the master as to applied blend shape, and retop that.
  2. Never retop the base model but export it to Maya right away. Once you finished retop on the copy export that to make sure that Maya will accept it as a legit target.
  3. No idea as it’s a problem to figure out via discovery but as long as the blend shapes work you can do more or less anything you need to do Maya side and send it to UE4 via FBX.

As a suggestion if your interested in procedural character creation you should give Daz Studio a go. It’s the right tool for the job, has a GoZ bridge to send a genesis model over to Zbrush, and there are plenty of video tutorials on YouTube on how to make injectors and morph targets as well as modeling clothing in Zbrush and make use of tools with in Daz Studio to make things fit and export the package out to UE4, 4.13 or later.

14

Hey thanks so much for the reply!

Wow I have to say your experience and knowledge can easily be seen in your suggestions and acronyms.

Im embarassed to say I barely understood much!

Please bear with me, Im really still learning technical talk as I go, so there were quite a few things I was hoping you would be able to help out with >o<

What is the master as to applied blend shape mean?
And how come I need to make a copy of the base model? Shouldnt I be exporting the base model(Left side mesh) as a OBJ to bring into Maya for Quad draw?

So you mean if I export the base model to Maya and do the Quad Draw retopo on it, then…whats a legit target?

Whats procedural character creation?

Whats a GoZ bridge?
and a genesis model?

I actually was wondering about this before.
I know how to set a morph target in Zbrush and use the morph brush

But even searching up a morph injector on YouTube I never found anything.
Is injector a nickname of some sort for morph target?

I was actually thinking of using Marvelous Designer to model clothes, but I know you mention ZBrush for a logical reason I dont know yet…
Was it because ZBrush fits with some kind of workflow?

Would Marvelous Designer be okay for the whatever it is you were thinking of?

15

You’re gonna love this: http://www.russian3dscanner.com/

16

As a starting point as to understanding figures in Daz Studio this is a good start as to explaining the basic.

A blend shape is the word use in Maya as to what is a morph. You want to use a copy of what will be the rigged character as exported so that you can make more blend shapes based on the requirements to make retop work the way it should. You can reshape the copy any way you wish but you can not add or remove details the will change the vertex or surface count between your original and copy if you want all of your characters to share the same frame work.

As mentioned a ligit target is an object that shares the same number of vertices and surface count and if added to or removed at the sub-object level what ever application you are using it in will no longer accept it as a target shape.

I don’t know what Quad Draw does but our character developers are all now using Zbrush/Daz Studio as moving stuff over to 3ds Max has come some what redundant.

Procedural means procedural as in the shape of your character can be changed by selecting and changing a set value of an area of your character which you wish to retop using morph reshaping and you can purchase morphs for both head and body and use that instead of doing a retop in say Zbrush or whatever 3d app you wish to use.

A bridge is a means to move a working asset from one edit environment to another with little or no loss to fidelity of the base asset. Daz Studio supports a few bridges to say Photoshop or Hex 2 so since you are using Zbrush if you install the GoZ(brush) bridge you can send a Genesis model over to Zbrush at the push of a button.

Genesis is a Daz3d product used in Daz Studio as a base alpha character that other characters can be built on by either buying Injectors, more on that later, or by making your own from scratch bt still make use of the basic requirements like UV mapping, base rigging, morph and cluster shapes to do lip sync and facial expressions. As a perspective kind of like you have a male/female brush shape to use as a base in Zbrush.

OK an injector is a term used in Daz Studio that defines a ready made character that can be “injected” onto the corresponding Genesis framework. There is a Genesis 1 2 and 3 as a starting point and if you wish can purchase say Victoria 7 as a ready made character and from there other characters are available that require Victoria 7 as the base.

So in this case the layering would be Genesis 3 > Victoria 7 > different and unique character.

So yes it is more or less a full body morph but named different as to avoid product confusion as to morph targets that are also available as part of the Genesis collection. You can purchase complete morph sets for body and head for male and female. Keep in mind there are other parametric characters available for free under Creative Commons but we found Genesis 3 as a product fits well as to video game requirements.

Well anything that supports FBX could be included into the preferred application list of any pipeline so if you are using Marvelous designer, and it supports FBX, then it’s an option. Would love to see what someone does with Houdini in UE4. :wink:

We opted to use Daz Studio as a cornerstone application as it’s suitable as to our need to have a complete framework solution that works with both code and content and by paying a few bucks for the license solves a lot of back end requirements that we can scale up no mater where the assets come from.

Hope that helps…a bit.

17

Thanks !

Im not quite sure why a blendshape is needed in this process?

I thought I was going to …
1)do the retopology using the retopology tool in Maya called “Quad Draw”

2)then bring that back into ZBrush so that I can use the reproject function?

*And i thought my problem was not knowing whether to do step 1/retopologize the base mesh or the HD completed model for retopology?

If Im doing any reshaping though that would be in Maya right?
Im actually only decent with sculpting in ZBrush

18

OK I had to check out what Quad Draw does and that will not work if you want all of you character models to “share” the same topology as it is new mesh detail that does not follow the rules of morph or blend space creation.

The “only” reason to share topology is to be able to create a single base character fully rigged as to requirements with a set up necessary to support lip sync using either morphing or clusters as well hundreds or even thousands of different materials being applied as the UV map is the same between every iteration of the the same base.

Once you have the base done then you can change the base shape by remodeling the mesh into the desired shape so you could remodel a 6 foot 35 year old female into a 4 foot 12 year old and all of the facial morphs as well as animations applied to the base rig will function as it’s all additive.

The benefit is one can then create thousands of different and unique character models that all share the same animations, driven by lip sync animations, cross share materials like eyes and hair styles as well provided you players or clients with the means to make custom characters. Would be easier to demonstrate if UE4 did have a morph loader as in if you were using the Genesis 3 base, an already functional parametric character, you would just have to remodel the base shape to what you want, load it in as a morph, and tada you have a new player model all wired up ready to go.

I guess it was confusing stating the retopology is a requirement as the different characters you can make share the same topology but are in fact needs to be remodeled off of the base model to maintain the ability to share.

19

Hey I think I need to lay out all my tools so we can be on the same page and really understand each other.
Because I love the end results of what youre talking about to be able to share everything amongst everything, but it seems getting there right now there is a lot of conflicting tools maybe I want to use and you didnt use or you have used and I haven’t.

So here it is the full layout and hopefully you could tell me what will and wont work or how to make things work to get the same result you mentioned!

For the “fully rigged part what exactly is a set up that is necessary to support lip sync” ?

For Rigging) Im planning on using the new version of Blendshapes/Morphs in Maya called Shape Editor for most of the rigging
As well as joints for certain parts like the eyelids.

Heres a short 1 minute clip showing what Shape Editor does…https://youtube.com/watch?v=b7AEeLm4Lug
For Animation) Im looking to use a facial Mocap called Faceware for my animations

Heres a quick 2 minute demo if you wish to seehttps://youtube.com/watch?v=MwgSDj0qvp0
For retopology and UV creation) Im looking to use Maya Quad Draw for retopo and Maya itself for UV as well

For Texturing) Im looking to use Substance Painter

For rendering) Im looking to use UE4

For modeling) Zbrush

Now that Ive laid out everything Im looking to use…
**
Current problems**

1) I’m at the texturing stage and I need to do the retopology and then UV map.

The reason why I need to use Maya Quad Draw is because I cant get any clean topology like The Order 1884 has without doing it by hand.
And in ZBrush the only way to get retopology is with ZRemesher and it cant give me that type of clean topology in the pictures of The Order.

(Which is shocking to me because for some reason The Order 1886 has split the model, it seems, judging by the different colors that they are poly groups, but in ZBrush? How did they even get the topology that clean in ZBrush in the first place…)

Now, the only thing that has me wondering is then…

Both my base mesh and high poly mesh I sculpted by hand
so the topology is all over the place…
**

How do I get better topology if I cant use Quad Draw?
(As mentioned above, ZBrush has no way of getting clean topology like The Order pic, because they only have Zremesher)

(So right now, I need to retopologize, but I just dont know which mesh to do it on
and right now it seems Quad Draw is no good as well?)

2)
The only reason Im stuck on this retopo phase is because I want to,
in the long run I want to be able to also have future characters be able to share the topology so I dont need to retopo everytime.

3) And if possible, also even share some of the basic Shape Editor and joint driven rig…
…so they can do simple functions like blinking and opening mouth and so if I want a difference I can just redo some of the other mouth opening rigs instead of redoing everything from scratch.

20

Sounds to me that your still at the modeling phase. No point in how to share ready made assets until you have something in hand to share and usually the need to share is based on a much more complex objective.

Whats your plan? Do you have a link to the Order 1886 decision? Do they discuss why they took this approach?

21

Sounds to me that your still at the modeling phase. No point in how to share ready made assets until you have something in hand to share and usually the need to share is based on a much more complex objective.

Whats your plan? Do you have a link to the Order 1886 decision? Do they discuss why they took this approach?
[/QUOTE]

Modeling has finished, Im looking to do retopo
and the only thing stopping me is the possibility that this could be shared amongst possibly later characters.

The short term goal is to make a short cinematic where the character moves and talks for testing,
later on Im planning to then put the character into an environment for a story that is in the works.

Here is the link to the discussion

Look at pg 36