I am working on converting a piece of CC from sims 4 to 3. I did some google foo and realized most of my failed exports were not exporting with the right group name because I hadn't actually saved the group name in the original blend file. I saved, closed, reloaded and confirmed it was named group_0 like the mesh is in the original TSRW.
No success.

I remembered the last time I had this issue it was something to do with export settings, so I tried tinkering with those. Nada.

So after doing everything I can think off to get this to work I am asking for help.

I did combine the original Sims 4 mesh into the original group, that is the last thing I can figure that might be causing the issue but I have zero idea what to do if it is.

I have included all the failed export objs, the blend file exporting, the S4S file, and the TSRW file in a zip folder.

If anyone has any insight into what I'm doing wrong here I'd greatly appreciate it.

What is your work flow? I don't see any .wsos in your files, so how do you import to TSRW? You can't just import as object to TSRW. That sometimes works with game objects, such as statues, plants, but not Sim garments.

There are a few minor mesh issues, such as faces between adjacent parts that appear to have been solidified, but that isn't the issue. You also have a stray edge, where the waste should be, and a gap between your mesh and the TS3 top. Again, not the cause of the issue you have.

You need to export as object, use MTK to convert to geom, add bones, seam fix and convert to .wso. Bones are another problem, since after a basic transfer, you'll need to remove some bones and hand paint... otherwise, your Sim/ game mechanics will make the mesh try to walk. Your mesh poly is high, so after adding morphs, L2 and L3 will have to be heavily decimated, or your meshes will explode.

And with no EA or similar mesh to transfer bones or morphs from, the morphs will also have to return to Blender to be hand adjusted.

Ok so right away I can see an issue. I actually did not know you can't import a .obj for sims garments, I've only ever converted objects and maybe one accessory years ago.

My work flow:
Export from TSRW as .obj.
Open blender, and start a new project file.
Delete the default cube and import the .obj file.
Export the sims 4 blender file, and use append to get the object from the blend file.
Delete (most) of the vertices on whichever TSRW mesh I am using (This is the waist line you are seeing. This is a reference point to help me make sure the final product is as seamless as possible. Due to the issues I was having with getting the mesh into TSRW, I did not finish the original or subsequent meshes).
I then selected the original "group" and used merge objects to join the sims 4 mesh into the original group.
I then exported as objects, and then tried grouping.

I will look into the other steps you mentioned, I think I need to do a bit more research.

I am unfamiliar with MTK, can you elaborate on this step?

OK. So, you've never converted a garment before. There is a bit of work, the way I would do this conversion...

Export the mesh from S4S and import Blender file to Blender. Select mesh and export as object groups. Open new general file in Blender. Import S4S object. Select all and merge by distance 0.0001. You'll see odd shading on the straps where there are unnecessary faces. On UV side, select the faces and delete.



Import an EA af nude or bikini bottom. Hide the tail. Select all except top row of faces and delete. Unhide tail.

From side view, set viewpoint shading to wireframe. In edit, set to vertices select, and select a few rows of the tail near waste. Move waste back using proportional editing set around 0.200 and center front to back. Next, select top row and resize with proportional edit on, to better align to TS3 waste. In front view, resize to match TS3 waste. You'll have to adjust the area where there is a gap, by resizing on X axis and move forward a bit.



Starting at front, merge the bottom vertex of the TS3 waste to the top of the tail using merge at center and UV's OFF. Repeat this for every matching pair. You can use wireframe, but be sure not to grab wrong vertices! At front pelvis, merge all 3 vertices. Other option would be to subdivide tail mesh edge and merge. There is similar at back of pelvis. Select the edge you just merged and split faces. On UV edit, you see gaps on the edges of that seam. merge each gap. If you had auto merge UV, there would be a messy spider web between the meshes, so do it this way to preserve the UV. Now, select and merge the edge by distance.

I set select sharp edges to 60 degrees. That's my preference. Note, there are no backfaces to the "fins". We're already over 5,000 vertices, and adding them will be another 546, so I skipped it for now.



Last, for whatever reason, this mesh sits 10 units above the floor. Select all and merge by distance. So, in wireframe viewpoint, select the vertices of the bottom part of the mesh, along the floor. Move them down to approx 1 line above the floor, at the Z axis line, and click proportional edit, then adjust it to 0.300. You'll see the mesh "smooth" out. This allows for rugs, which sit above floors, and isn't noticable in game. You see toward the end of the tail is below floor. Select vertices, about as shown, and move up to the 1 unit above the floor line, click proportional edit, and adjust to around 0.100.



Once again, select all, merge by distance (just to be sure) and Mesh> Normals> Average> Corner Angle or whichever you prefer the appearance of. Import an EA top. I use bikini. Select both and go to edit mode. You have a tail that is aligned to TS3 top.



The tail UV is in an area that EA reserves for top parts, so part of it must be moved. Post when you get this far, and I will continue with texture and UV alignment.

I cannot express how grateful I am for such an in depth tutorial. I will absolutely update when I do. I will probably be able to this weekend, but I'm itching to start, so maybe sooner LOL.

Thank you so much!

VERY pleased to say that I finally got some free time. I am pretty dang proud of my waist merging (I wound up using subdivide for the sides), it's dang near flawless!

Looks good. Not to be a Debbie downer, but from the pic, it looks like you subdivided on the top row at the waist seam? If true, that will not match the EA TS3 top seam. When matching TS4 bottom to TS3 top, you need to preserve that top row of edges/ vertices.

I'll find some time to work on the next steps, which will be to export as object, convert and add basic bones in MTK, then paint bones in Blender. Honestly, as I don't have TS4, and cannot see the bone of the original, and I have never tried such a bottom, I am only guessing about bone layout.

I subdivided the tail but I think I messed up the vertice merge in a couple spots, It's fixed now and I checked it against the EA base body top and NOW it actually is flawless! perfect vertice to vertice contact .

As for the bones I do have a couple other tails (serpenty mermaids) and I think from the way they move it's just following the basic skirt bones, it just makes the tail swish (wag?) when the sims is walking.

Hmmm.... Could you send the geom so I can look? I was thinking to remove all the bones from one side of legs below the pelvis and paint them to the geom, but if you have something you can use as a donor, great!

MTK is quite easy. Export your mesh as object. You don't need to worry about splitting seams, as MTK does that during conversion. So, export as object. Use MTK to convert, Conversion Tools> Object to Geom. Then, Auto Tools for Geoms> Auto-Assign Bones. Next, Seam Fixer. This tool works on af L1, but several option do not. I have Blender 2.80 with Smug Tomato's Geom Tools for L2 and L3, and tf.

Once bones are transferred, back to Conversion Tools> Geom to TSRW WSO. Finally, Auto Tools for WSO> Auto Create Morphs. You'll see that MTK can also transfer bones from .wso to .wso, and seam fix them.

The only thing about morphs is that they 100% depend on the donor mesh, and may make a slight mess, especially the fat morph. But, we'll cross that cluster fudge when you're ready.

Sure thing! I included the mermaid and the snake. I used S3PE to extract all the geom files, but I included the package files in case I misunderstood what you were asking for.
For MTK I am using this one: https://thornowl.tumblr.com/post/75...-seam-fixer-fix which says it has the missing data? Guess I'll find out LOL.

As per the morphs, lay it on me. I've got a wide open weekend and tunnel vision for projects LOL. Would the morphs have anything to do with why full body outfits can be tricky? I read that somewhere recently, that they need extra steps or something. I'm hoping to do a few conversions so I'm just enjoying learning all this stuff.

I had Thornowl's version and misplaced it in my mess. As I recall, it does L1, including teen, but not L2 or L3, which I actually do fix seams on... just because I can. I'll take a look at the mesh today.

The way MTK morphs work, is that the program moves vertices from point "A" to point "B". Since the donor mesh vertices usually aren't exactly the same as the mesh being morphed, the program "guesses" where point "B" should go, which might not be accurate. As the note says, the more similar the donor and mesh to be morphed are, the better the results. Fat morph moves vertices furthest, so a greater probability of error in the morph.

After I have time to check the mesh you sent, I'll do a quick tutorial for you.

Quick update. I put this together in TSRW, and the morphs cause the Sim's hair to explode. This is caused by the high polycount with morphs added. I will need some time to go thru the tail mesh to find the best way and least amount to reduce polycount while preserving appearance.

I figured it'd be a tad wonky. I've been working on a few blender files for this project (Overall this is for a themed world), and one of the statues that was a MESS no matter what I'd tried actually did a lot better using the collapse filter under decimate.
I don't know if that would work well for sim garments, but it did wonders for a statue that had been an absolutely mess using the methods I found in other tutorials.

Also thank you so much for all your help thus far!

I'm putting another test tail in my game today. I'm playing vampire king and queen who took over Praaven that is lived in by elves! So, another mythical creature running around fits.

I have a program, BalancerNPro, which I use for some projects. It tends to preserve seams if not reduced too much. I separated the main tail from the other parts in Blender, and only reduced the tail, since the other parts looked pretty decimated already. L1 is around 4800 vertices. L2 and L3 test are heavily decimated, and the extra parts removed, but no mesh explosions. I'm also working on texture alignments as I go and tweaking bones.

That sounds like an AWESOME save to play! I'm trying to do this tail for the new gorgon occult mod if you want to add a little extra spice to it. I saw and was like "Gorgon? Lean full on into snakes and make 'em nagas". Now I'm designing (and nearly finished with) a world just for this one mod LOL.

I've never heard of BalancerNPro, but I'll have to check it out for sure! That vertice count is pretty good! Better than most of my own attempts for sure!