引用自 Zappy：

Did you mirror the left arm to make your right arm? If so, depending on how you did it, you might have ended up with the right arm being "inside-out". Try to select the right arm in Blender's Edit Mode, and then "Flip Normals".



(Usually, the model being inside-out would result in you not even seeing the "outer" side of the model in Source, but it looks like that the material has $NoCull enabled, which makes the back-side of mesh render... but the back-side still calculates lighting from the front-side, leading to the inverted illumination.

Unless you really need $NoCull for something, I'd personally suggest to leave it disabled at all times. And when you do need it, I'd usually suggest still leaving it disabled, and just making a copy of the mesh itself with its normals/faces flipped, so that it'll calculate lighting correctly on both sides.)

Thanks <3

Well, i guess i'm right to posting here...

ok, so the thing is that i'm new creating models for source. the first model that i'm trying to make it's a weapon model as you can see on the screenshots.

the problem is that as you can see on the first image is that the right arm looks pretty bright,
but on the second one (this is the model that i'm creating) the right arm looks quite dark, while the left arm looks pretty natural.

the models as been placed very closed each other, so the light is same on every model.

I'm creating the models with blender...

https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2101474000


https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2101474179