Rendered position of world models from AddCustomWorldModel freezes after PVS exit

[Guy-L]

TTT2 Version

v0.14.6b. Directly extracted & locally ran the latest version of TTT2 base from the workshop via gmpublisher.

Description

Certain weapons do not use a standard "default" worldmodel, and instead build their worldmodel via TTT2's AddCustomWorldModel. If such a weapon is thrown on the ground and it exits the client's PVS, its rendered position will become permanently fixed where it was when it exited PVS. It will continue to render there even if the actual entity moves around, and will be rendered only if the entity's actual position is on screen.

This issue can be experienced with all base TTT2 weapons that rely on this system (radio, binoculars, decoy, beacon & visualizer). Note that the correct position/angles for the model seem to be computed at line 307 of weaponrenderer.lua, but are only applied if the hasHandBone check passes, which is impossible for thrown world-models as the "boneEnt" is no longer a player model.

Expected behavior

The worldmodel should render at the correct location/angles, i.e. those obtained from line 307 of weaponrenderer.lua.

Video (only TTT2 base & ULib/ULX installed, local server)

https://youtu.be/BWsCz34wJqQ

I used noclip to quickly showcase a PVS exit, although it's obviously possible and common in real games.

Possible fix

I was able to resolve the issue by adding the following lines to weaponrenderer.lua:

            else
                model:SetPos(posModel)
                model:SetAngles(ang)
            end

Right before model:SetMaterial(modelData.material) in weaponrenderer.Render.
I am not overall very familiar with this code, so there may be side-effects to this change that I'm not aware of.
This may also fix the symptoms of the bug & not whatever the actual bug is.

[Guy-L]

I've found a temporary solution I can use before this is fixed; simply adding this to the affected SWEPs (client realm):

    function SWEP:DrawWorldModel(flags)
        self:DrawModel()
    end

This skips the base class' call to weaponrenderer entirely & makes things work as you'd expect. It may not work for weapons with more complex composite worldmodels (which is what AddCustomWorldModel is built for as far as I understand)

[saibotk]

Oh that seems odd, thanks for raising the issue!

The possible fix seems fine, though i'd like to have @TimGoll's opinion here.