`prop_physics` model scale is not applied clientside causing prediction errors

[RaphaelIT7]

Details

prop_physics that have a model scale are missing their clientside :Activate() call, which is why their model scale has no effect clientside. Running Entity(x):Activate() clientside solves the prediction errors since then the model scale is applied properly.

This issue also exists, when duping a model, as then they have :Activate not called at all, and their server physics also then return to the normal model's physics.

I think the best way would probably be to have a new networked value like m_fAppliedModelScale that is set when serverside :Activate() is called/when the physics get scaled serverside, and the client can then use that variable to apply the model scale clientside for physics, this would also allow dupes to properly work as props might not always like their physics to be scaled and only use it for visuals, or some might set the model scale to 2, call activate to scale the physics, and then change the model scale again, so m_fAppliedModelScale would then allow you to keep track of what the physics should be scaled by and avoid possible issues.

Steps to reproduce

1. Have a map entity with a prop_physics that has a model scale
2. Run cl_showerror 3
3. Walk into the entity and see all the prediction errors

[Grocel]

This issue has been seen on a small test map made for wiremod/wire#3351.

The test map, including vmf:
gm_wiremapinterface_v1-1.zip

For testing you go to the first floor on the back side. There is a cage like thing with a large ball in it. The Ball has a scale of 7 applied to it.

The scale also breaks when duped/saved. If engine saved/loaded the scale breaks as well.

[robotboy655]

This is kinda intentional because it never worked clientside (I can't find the issue) before it was fixed not too long ago, so it was made to not update automatically to avoid issues with existing content.

[RaphaelIT7]

(I can't find the issue)

You probably mean #5867

Maybe having a spawn flag for this or a networked var like m_bShouldApplyModelScale could be added, but that would be a net compat change. Though it would allow people to then decide if they want their stuff scaled or not.