Basic retargeting questions

[Sekhar]

Guys, I'm trying out some BVH with NevronMotion and would appreciate if you could answer some basic questions on retargeting for me:

1. Is the Nevron retargeting just a shortcut for bulk application of same-as-item on rotation? I.e., does setting up same-as-item one/one manually (for target bones to mimic source bones) do the same thing?
2. I see how to select specific source bones ("Get Selected"), but how do you specify the target bones? The Nevron presets have target names "Hips," "Spine," etc. Are we supposed to name the target bones exactly the same? Or does Nevron map based on whatever bone is closest to the selected source bone? All the demos just show the targeting process working magically regardless of what the target rig is, which I don't get.

 

[jwiede]

1. Is the Nevron retargeting just a shortcut for bulk application of same-as-item on rotation? I.e., does setting up same-as-item one/one manually (for target bones to mimic source bones) do the same thing?

I'm pretty sure it doesn't actually use same-as-item constraint, but what happens is that the source bones' PSR values are run through an algorithm to account for scale difference then written to the target bones' PSRs such that the end effect is equivalent to what you described. In fact, for rotation, I believe it is a direct transfer of the source value to target in most cases. That said, I don't think Nevron specifically creates a bunch of same-as-item constraints then freezes them for rotation transfer, if that's what you're asking, I believe value transfers are done a bit more "directly" than that.

2. I see how to select specific source bones ("Get Selected"), but how do you specify the target bones? The Nevron presets have target names "Hips," "Spine," etc. Are we supposed to name the target bones exactly the same? Or does Nevron map based on whatever bone is closest to the selected source bone? All the demos just show the targeting process working magically regardless of what the target rig is, which I don't get.

IIRC, Nevron is designed to retarget to specific target rig layouts (name templates), f.e. there is a Genoma "Nevron Motion Rig" target template. Again IIRC, Rhiggit's retargeting is more rig-generic w.r.t. target rigs.

 

[CaptainMarlowe]

I made some tuts some time ago explaining the get selected thing and how to retarget when the BVH is not standard or as some exotic bone names.

Part 1 :
https://www.youtube.com/watch?v=FCScfH7GooM

Part 2 (this one is the one that may interest you about bvh retargeting, get selection and preset creation) :
https://www.youtube.com/watch?v=9QmLLV96lKo

Definitely not professional tutorials, but it may help a bit.

 

[Ryan Roye]

Nevron's retargeting is good in the fact that it goes beyond same as item constraints and can compensate for differences in limb length when applying the motion to the rig. The downside with both Nevron and Rhiggit is that you are limited to the rigs (or rig parts) that you are provided with... these, like most other systems only expect themselves in the way that they work which is unfortunate. I would like to see this change eventually.

Nevron needs a lot of improvement and I feel certain elements of it were completely left out of its user interface. For example, if you want a preset to only include 14 items (limbs, body, head) rather than all the other bones that are seldom used in motion capture (toes, ankles, etc), you actually have to dive into notepad and manually create it via text editing using the existing presets (also text files) as a template. Furthermore, the user needs to know which bones are which in order to do a proper retargeting which makes the process very tedious when dealing with many different target rigs. If updates are made, I'd like to see setup become a more visual process like what they did with the parenter tool in 2015.

A third way to go about retargeting is to use IKBooster and same as item constraints combined with scripting to automate pairing. The advantage is that relative motions can be created to make your motions work on any rig that's derived from a template that you create, and motions always load relative to the character's position/rotation (and optionally, limb placement) in 3d space. A scalar null can be used to determine how strongly any IKB motion applies to a character. The downside here versus the other options is the learning curve which is substantially higher than Rhiggit/Nevron, so you need to understand Lightwave's constraint systems and such thoroughly to get the most of it. I do have learning content that covers this.

That said, all retargeting methods in Lightwave have their problems, advantages/disadvantages and it's up to the user to find out which is best for their production needs.

What Lightwave truly needs is simplified universal rig retargeting that does away with requiring the user to use certain rigs. If Nevron were to add that, it would increase the plugin's value quite a bit.

 

[Sekhar]

IIRC, Nevron is designed to retarget to specific target rig layouts (name templates), f.e. there is a Genoma "Nevron Motion Rig" target template. Again IIRC, Rhiggit's retargeting is more rig-generic w.r.t. target rigs.

Yeah, this is what I'm not following. My goal is to apply BVH and some Kinect captures to my rigs (not a select set of NewTek rigs), and I'm trying to figure out how to do the retarget thing. I'll explore some more.

 

[Ryan Roye]

Yeah, this is what I'm not following. My goal is to apply BVH and some Kinect captures to my rigs (not a select set of NewTek rigs), and I'm trying to figure out how to do the retarget thing.

Nevron does not do this. You must use the Nevron Genoma rig to benefit from its retargeting functions. Again I'd love to see this change at some point.

 

[Sekhar]

Nevron does not do this. You must use the Nevron Genoma rig to benefit from its retargeting functions. Again I'd love to see this change at some point.

Thanks, that is really good to know. I wish NewTek makes that (the limitation) clear in their videos.

 

[RebelHill]

IIRC, Nevron is designed to retarget to specific target rig layouts (name templates), f.e. there is a Genoma "Nevron Motion Rig" target template. Again IIRC, Rhiggit's retargeting is more rig-generic w.r.t. target rigs.

Yep... nevron requires you to use the nevron specific rig on your target characters, it's the only option you have. RHiggit is more flexible, in that you can use any RHiggit rig (so you're not restricted just to biped, or one specific biped), but you still cant use any rig, as the retargeter still has to "understand" the structure of the target rig itself.

My goal is to apply BVH and some Kinect captures to my rigs (not a select set of NewTek rigs), and I'm trying to figure out how to do the retarget thing. I'll explore some more.

No can do, as mentioned above, you cant just use any rig. This isnt really an uncommon limitation in other apps either. Even though you can use your "own" rigs in motionbuilder, etc... They still have to be structured a certain way, and contain certain default "parts" in order for the retargeter to understand the target (same goes for the source)

You can, as you suggest, stitch something together manually by aligning parts and using SAI to constrain things to each other... its just a bit of work and attention needed, so you may be better off in the end using a ready made solution.

 

[lightscape]

If updates are made, I'd like to see setup become a more visual process like what they did with the parenter tool in 2015.

+1000000

I mentioned the same thing a while back in a thread somewhere maybe regarding Nevron. Its trial and error to setup because mocaps sources are not the same. It needs to be visual like in Modo. And I know that Rob Powers said that Nevron will never be a part of lightwave in the future. Big Mistake! They already sold it to early adaptors and got their efforts paid so why not include it with the genoma toolset. People won't mind if the end result is a better lightwave.

Modo retargetting has visual aids that make it a lot less cumbersome and trial and error.

 

[jwiede]

They already sold it to early adaptors and got their efforts paid so why not include it with the genoma toolset. People won't mind if the end result is a better lightwave.

Hmm. Normally I'm pretty tolerant in that scenario, but in this case, given how quickly LW3DG stopped supporting Nevron, how little support they did provide, and its retail price as a plugin... If it were to be integrated into LW I'd definitely expect existing Nevron owners to receive a discount (around $100 off seems fair, applicable with HC "discount") on the LW upgrade where it gets integrated.

 

[Mojo_LA]

Reviving this old thread, hopefully someone out there is still paying attention!

I need to do some mocap retargeting. There are a lot of options now for mocap, you can do it with your phone or sites like Wonder Studio let you upload a video clip and it will return a Blender FBX of a moving skeleton.

I need to apply that mocap to characters in LW that have been rigged with either Genoma or Accurig (Real Illuision).

I'm looking at Nevron, Rhiggit and iClone as possibilities.