Originally posted by The "Big Iron" Click Bait:

I have also had this issue with importing animations. The bones on a lot of the CS:CZDS models being flipped is a pain to fix manually. Would love a fix in the tools for it.

you may have seen it before but for others I have a temp fix here which I reference in my GoldSrc guide
( the303.org/tutorials/gold_mdl_blend.htm#IM ):
1) import ref mesh, this will look fine but of course is bone flipped
2) in notepad open the ref mesh smd, and copy everything from the start all the way till the end of the skeleton block end (do NOT go into "triangles".)
Paste that into a new document and save as "posefix.smd"
3) back in blender import "posefix.smd". It will now look broken, but go into pose mode, select all then "apply pose as rest pose".

Ive had multiple run ins and recently troubleshooted several friends projects where they ran into the issue where they import a model and the reference looks fine, but some bones are flipped so when any animations load the whole thing breaks. This happens on both Source and GoldSrc imports.

My previous threads referencing this:
https://steamhost.cn/steamcommunity_com/groups/BlenderSourceTools/discussions/0/1744479698794920993/
https://steamhost.cn/steamcommunity_com/groups/BlenderSourceTools/discussions/0/2626094856506910191/
https://steamhost.cn/steamcommunity_com/groups/BlenderSourceTools/discussions/0/2788243698220275472/

Can also confirm this happening in Source engine models too. Gmod Citizen C_arms, the right forearm flips without knowing on import. Spent a huge amount of time troubleshooting to find its once again this same issue.

This is the same bone flip import issue ive had with GoldSrc models for a while now and have previously brought up in bug reports twice now:
https://steamhost.cn/steamcommunity_com/groups/BlenderSourceTools/discussions/0/2626094856506910191/
https://steamhost.cn/steamcommunity_com/groups/BlenderSourceTools/discussions/0/1744479698794920993/
I hope this gets visibility since this has been ongoing

Ill also repeat for anyone reading my hacky fix for now:

1. import ref mesh, this will look fine but of course is bone flipped
2. in notepad open the ref mesh smd, and copy everything from the start all the way till the end of the skeleton block end (do NOT go into "triangles".)
Paste that into a new document and save as "posefix.smd"
3. back in blender import "posefix.smd". It will now look broken, but go into pose mode, select all then "apply pose as rest pose".

This issue exists in the old 2.79 and current BSTs and affects many models.

Ive figured out a temporary fix for those experiencing the "bone flip" import issue; it seems like reference mesh is affected but anims are fine so i made up this workaround:

1. import ref mesh, this will look fine but of course is bone flipped
2. in notepad open the ref mesh smd, and copy everything from the start all the way till the end of the skeleton block end (do NOT go into "triangles".)
Paste that into a new document and save as "posefix.smd"
3. back in blender import "posefix.smd". It will now look broken, but go into pose mode, select all then "apply pose as rest pose".

Ive been finding more and more models that have this issue especially the SD models like the headcrab zombie and a few others

A change from the 2.79 version to the 2.8+ versions I found was that when you set material order in the materials list, it gets ignored in the 2.8+ upon writing the SMD. Specifying this is useful in goldsrc due to managing sorting issues when using additive planes. I confirmed this by testing the two versions:
http://www.the303.org/imaeg/smdbstorder.png
The method im using is here which works in 2.79 if curious to know what I mean:
http://www.the303.org/tutorials/sven_fullbright.htm


A second issue ive found is this particular model when imported into BST even with no changes and exported jumps in position significantly:
http://www.the303.org/imaeg/smdbstmovement.gif
One or more of the bones have moved in position (the physical mesh/verts are fine, and I imported both smds without bones and the meshes match) causing the gun to move.
the files to see are here:
http://the303.org/stuff/9mtesting.zip

Third issue but possibly related to the above is the 180 flip issue where some models ref SMD have bones flip 180 degrees upon import, causing all anims to look broken when run. I have a thread about that here and im getting this still in various models:
https://steamhost.cn/steamcommunity_com/groups/BlenderSourceTools/discussions/0/1744479698794920993/

Lastly, is it possible for an auto-weight threshold (1 influence per bone) for goldsrc SMD exports? skin weight issues happen a lot with goldsrc users and having a threshold operation or slider on export would be a great tool for GS users.

I just upgraded to the latest BST and each time I do an export; it makes a duplicate copy of the active mesh and skeleton (mesh.001 & skeleton.001 i see in the outliner after I export)

I had an issue similar but I found it was the zip package itself was the error so I (and another person did this as well):
Unzip Blendersourcetools-master.zip, extract the folder to Desktop, re-zip Blendersourcetools-master folder into zip, run Blender, install the new zip and it worked. Had to do with the zip with the additional folder, so when rezipped without the nested folder installed correctly.

Originally posted by Pte Jack:

GoldSrc is an extremely old engine, not many of us work with it anymore, so finding information after Valve coverted Halflife to the source variant is pretty hard. lol

Hey, ive been writing modernized guides on GoldSrc model workflow:
http://www.the303.org/tutorials/gold_mdl_blend.htm (blender specific exporting guide)
http://www.the303.org/tutorials/gold_mdl.htm (general Model workflow start)
http://the303.org/tutorials/gold_qc.htm (goldsrc specific QC commands)
http://www.the303.org/tutorials/gold_mdl_fix.htm (model compile troubleshooting list)

So trying to help someone out I found a very odd error with SMD importing (In goldsrc model) where BST would flip the bone position of the head, pelvis, and left&right feet. When imported the mesh looked fine but the bones were wrong so when i exported the animation was flipped.

I took the reference SMD and imported it with 3 other 3D SMD editors and did not have this issue. I then re-exported the reference SMD with 3dsmax and when I imported into BST, it imported correctly. Im assuming its something to do with how the original SMD was formatted that possibly had something on those bones that made it invert on import.

This is what an imported animation looks like on the original SMD (broken ref import):
http://www.the303.org/stuff/BST_refanimbroken.PNG

Attached I have the original SMD that fails to import into BST called "Original_ref". There is a regular animation to test with to see how its broken on the ref. There is a second SMD which is the re-export from max which imports into BST fine and with that the test animation works with it on import:
www.the303.org/stuff/BST_smd_importing_error.rar