Smooth Corrective: Blender's "Magic" modifier

[@wheany]

If you haven't seen it before, there is an addon called "Corrective Smooth Baker" which will pose an armature randomly, observe what how Corrective smooth alters the mesh, then try to automatically change the weights so that the pose is less distorted even without the corrective smooth modifier. It is included with Voxel Heat Diffuse Skinning addon, if you already have that.

[@wheany]

The addon warns about not working well on armatures with constraints, but you can work around this by doing the following: 1) export the mesh and the deform bones, without constraints, control bones or mechanism bones. 2) reimport the exported mesh and armature 3) add the smooth corrective modifier to the imported mesh 4) run the addon 5) use a Data Transfer modifier to copy the weights from the imported, smoothed mesh to the original mesh

[@kloa4219]

you are so awesome

[@pineapplepizzasandwich1974]

O: !

[@TioMegamanX]

That's quite useful considering almost no game engine seems to care for corrective shapes.

[@wheany]

@@TioMegamanX it's my understanding that that is one major reason why the addon was developed

[@bigboss9150]

It's practically mandatory to use with rigs in Blender lol It really is a great fix

[@krookedking6979]

Dude, your channel saved me a lot hours

[@CGDive]

glad to hear that!

[@MRUStudios]

Wow! Thank you so much for the great tutorial on this modifier, my friend! I have characters I've imported into Blender from DAZ Studio and applied clothes to them designed in Blender. I then re-rigged everything using Auto-rig Pro. I also did some manual weight painting. I didn't know about this modifier. It definitely will help with a number of issues U have! Thank you so much again for the tutorial, and for all of the great work you're doing on your channel to help all of us on our 3D art journey to share our stories with the world. I wish you success with everything you do. .....and I wish all of us the best in 2023! 😃

[@CGDive]

Thanks and keep up the good work!

[@sundaylee91]

Vertex Group is useful in certain cases, for example, when I use smooth corrective in one of my rig, the characters' wrists are affected somehow, since this modifier's main usage is to correct characters arm pit and shoulder shape, I use vertex group to isolate arm pits and shoulders area, and yes , it works like magic.

[@CGDive]

Thanks for the input. Yeah, this is something I realized after releasing the video!

[@bond1_mjblosser]

For 3ds Max users, this is the same as the Delta Mush operator in the Data Channel modifier.

[@zhehengqu]

I was confused about the modifier: Smooth Corrective。 Thank you so much for the explaining, it really gets me deeper into blender。

[@CGDive]

Glad it was helpful!

[@STobiasNilsson]

OMG! Thank you! I had never heard about this. I even asked in a Facebook group for something like this and no one seemed to know about it. This was so helpful!

[@CGDive]

Awesome, glad I could help!

[@Alex-eu6rw]

amazing, this fixed my issues I was having with my model. Thank you so much.

[@CGDive]

Glad it helped!

[@jinn_animation]

i always see modifiers on rigs but i never actually know what they do this really open my eyes.

[@CGDive]

awesome!

[@BlenderBob]

Thank you so much! That's super helpful for me.

[@CGDive]

*Hey everyone, Blender Bob commented on my video!* haha Love your channel and I am glad you found this useful.

[@BlenderBob]

@@CGDive I just realized that I can use this with the videogrammetry stuff we are working on right now. I will do a clip about it soon. Then again, I've been saying that since December... I'm a busy guy...

[@CGDive]

​@@BlenderBob To smooth out 3d scans, I think Smooth Laplacian is the one you want. Corrective only works when there is something that deforms the base mesh. But maybe I don't understand how you intend to use it. :)

[@infotoons212]

Thanks, I'll try it out today.

[@AnthonyRosbottom]

Wow! I never knew this modifier existed! Thanks for the great explainer video.

[@FlowerPower3000]

Thank bro, very cool!)

[@CGDive]

Thank you too!

[@JuanFernandez-ti5bv]

Great tutorial! thank you very much

[@zapmonkey123]

Super cool stuff! Gonna try it out :)

[@poochyboi]

are you able to apply the smooth modifier to certain parts of the body? - the smooth modifier affects skin detail like veins and pores (smoothing them out). Would be nice to apply it only to the distorted areas.

[@CGDive]

This video is about Corrective smooth, not Smooth.

[@thomasburbage5450]

I think what you're asking about is answered by the Vertex Group input, to isolate the effect.

[@warpedworks2177]

This is a killer modifier. Mixing this vertex groups and or drivers is really powerful. However, it's broken when scaling the root bone of a rig significantly though. Scaling of the whole rig should done in Object mode, NOT Pose mode, to ensure the corrective smooth doesn't break. he same is true for "Preserve Volume" on the armature modifier. I believe it's on their list of things to fix for animation 2025.

[@CGDive]

Maybe that's what the Scale slider is?

[@CGDive]

just tested it and yes! If you scale the root bone say 2.4x, then just set the Scale value of Smooth Corrective to 2.4 as well and it will start working as expected. So you could make a driver that links the Scale value of the root and the Scale value of the modifier to automate it. It only works with uniform scaling tho...

[@warpedworks2177]

@@CGDive Great! I'll test this in my rigs as well

[@XINN1X]

Should the Smooth Corrective modifier go before or after the Subdivision Modifier? What about Solidify Modifiers?

[@CGDive]

I would place it beofor subdiv/solidify.

[@HampsterGirl]

This is just perfect for me 😀 It saved me a lot time 😀

[@dyoanima]

Is there any way to burn the corrective smooth effect on the mesh weights?

[@CGDive]

yes: kzbin.info/www/bejne/gXWmdGWZpdJ7opY

[@ManaBlend]

Thank you so much, teacher! I have solved My avatar work rig the problem

[@KalponicGames]

Looks helpful

[@AdamIsailovic]

Interesting, thanks for sharing :)

[@CGDive]

Thanks for watching!

[@CGSparrow]

This is so crazy helpful and what a time saver. And the other stuff, I was wondering if there is a modifier that can detect self-collision, like when the arm and forearm bend, their surfaces intersect. Is there a modifier to prevent this? I tried the Soft Body, but it didn't work. The Shape Key is too time-consuming. Is there a better way to do this?

[@CGDive]

Ah, no... unfortunately, there is nothing for self-collision. I know Maya has something like that so it's possible, someone just needs to port it to Blender.

[@CGSparrow]

@@CGDive Then that's a little frustrating. Hope to see it someday.

[@Tenchinu]

wait… so u cant apply/bake it to the mesh like other modifiers before exporting?

[@CGDive]

Unfortunatelly, no... it only works as a "live" modifier because it actively detects the distorted parts of the mesh and smooths them.

[@Tenchinu]

@@CGDive my heart sore, only to be shot down :(

[@mcgoose258]

the closest thing is using the modifier to generate a shape key (blendshape) and then using a driver to motivate that shape key with certain joint rotations. that's clumsy but it can be exported and function in game engines. I will say currently this is quite difficult to do (just using the "save as shape key" option doesn't work as you'd expect) and isn't any more convenient than just making a corrective shape key by hand. but I also haven't tried this method more than a few times and between my own ignorance and the pace of blender's improvements, i'm sure it will be faster and easier soon

[@CGDive]

@@mcgoose258 That's a smart idea. But setting up the drivers etc still needs to be done and shapekeys in the shoulder area are a nightmare to set up. So there are still problems to be solved :)

[@blockschmidt]

Could I apply the modifier and eg export the FBX to Marvelous Designer to animated clothes there with the create FBX of Blender with the corrective smooth?

[@CGDive]

No, as I said it cannot be exported. Applying the modifier (as in pressing the Apply button) will simply remove it. Your only possible option for export is to have the modifier ACTIVE and export as Alembic.

[@skywolfe_games]

How can I apply this modifier? ... When I try to apply this modifier, it displays an error message saying that it's not possible due to 'shapekeys'. Even if I delete the shapekeys, they return to their original position, even with the modifier enabled... in other words, I don't know how to apply it, do you know how to teach me? Show message : Modifier cannot be applied to a mesh with shape keys How can apply ?

[@DanielPartzsch]

Thanks. So does this mean that when I export an alembic for dressing it in marvelous for example I'd need to apply the modifier before that so that I keep the same changes on the visual appearance?

[@warpedworks2177]

I don't believe you should "Apply" the modifier but leaving it on and unapplied and then exporting with the modifier still active in theory should translate to the Alembic export as this uses vertex positions. Test it out and let us know though. I'm curious

[@CGDive]

Alembic exports cached geometry so the modifier would need to be ACTIVE before export. Applying this modifier does not accomplish anything.

[@CGDive]

@@warpedworks2177 agreed.

[@sebyta7040]

To solve the problem of passing a character with the modifier to another software, would it only be necessary to apply it?

[@CGDive]

That seems like a common misconception. No, applying the modifier will not work because it actively detects distorted areas and smooths them as needed.

[@sebyta7040]

ah ok.. thank you very much for the answer.. I didn't know that..

[@ruudygh]

Is the same as delta mush in maya?

[@CGDive]

As far as I understand, yes :)

[@llYuki0okami]

Can't just save efect ot this as shapekey and convert to UE4 Morph Key?

[@CGDive]

Technically yes. But setting up the drivers etc still needs to be done and shapekeys in the shoulder area are a nightmare to set up with drivers.

[@HassanAli-sb7cc]

I want to Rig a character for Unreal Engine, should I have to apply this modifier before exporting to Unreal? Help anyone ^^

[@CGDive]

As I said in the video, this modifier is NOT exportable :) I heard that Unreal has a similar modifier (google "unreal delta mush"). So you may be able to apply it in the engine.

[@d-1379]

it will be cool, if we can bake this modifier to skin weights, and export to unreal or unity

[@CGDive]

This may be possible using a paid addon called "Delta mush". I still haven't tested it properly tho.

[@Akazki_]

@@CGDive "If you had already bought my Voxel Heat Diffuse Skinning add-on, please do not buy this add-on again, for I have integrated this add-on into the 'Voxel Heat Diffuse Skinning' add-on."

[@SalmanKhan-dx1ch]

sadly you cant just bake this into weights, because technically the anti-stretching you see here is in Realtime when it comes to weight painting without paid tools, data transfer modifier is your best bet

[@kloa4219]

can be done with the voxel heat baking addon

[@CGDive]

@@Akazki_ right, it's part of Voxel heat 👍

[@8D2BFREE]

wow wish i knew this sooner. In a few months i will need to go back to Maya, any one know a Maya equivalent?

[@CGDive]

I think it's called "Delta Mush" in other software :)

[@TheRhalf]

it didn't do anything to my mesh for some reason

[@CGDive]

It should do when the mesh is deforming from it's initial state. But just applying Smooth Corrective to an unreformed object won't do anything.

[@TheRhalf]

But deform how? with sculpting? I tried posing my mesh but it didn't do anything @@CGDive

[@CGDive]

​@@TheRhalf Not with sculpting. With Sculpting you just change the base mesh so there is nothing for Smooth Corrective to "correct". :) It needs a base mesh and something that modifies/deforms it. Which is usually a modifier of the Deform category. The most common use case is when you have a rigged mesh with an Armature modifier as shown in the video.

[@micahsonne3761]

See, as awesome as this modifier is, there is still a problem with it. Much like how Blenders rigging system prefers water-tight models, automatic weights will vary based upon the individual models. Even if you were to project the weights over to another mesh, topology and the overall mesh shape will cause different deformations. For example, a full base body with long pants. Parent the model to the rig, paint weights, and then parent the pants, transfer weights, then add the corrective smooth modifier to both models; the legs will still clip through the pants. This is something that has happened to me in my rigging process. The result will be different for both, because they posses differing topologies. The only real way to fix this is to have a "Delta Mush" system of sorts, and regretfully Blender doesn't have a native one; nor have I found one via third party.

[@CGDive]

Not sure if I follow completely but ... Smooth Corrective is the same algorithm as Delta Mush. Just a different name. And there is a paid addon called Corrective Smooth Baker which attempts to bake the effect of the modifier down to weights. blendermarket.com/products/corrective-smooth-baker

[@rbx3922]

how come when i add bones and pose them where i want, the entire model moves when i pose one the model has cuts in it and i want the bones to move the specific cuts

[@CGDive]

I don't understand the question. Is it related to the video at all?

[@alhusseinali]

So, what the point if it cant be useful in game engine! 💔

[@CGDive]

haha

[@wsoulless]

Cute for posing, but from what I can see on the video, it's totally useless since I can't: bake it in animation, apply the modifier on the weights, smooth a certain part of the mesh instead of all of it, export it.

[@CGDive]

It's very cute for animation as well, as long as you stay in Blender. It smooths out mesh distortions in animation as they happen. (do NOT Apply the modifier!) Yes, it's not exportable as I said in the video. There is an addon that kind of bakes the effect. I'll cover it soon.