Пропишите это в conf.ini и все тени будут работать
[Render_OpenGL]
TexQual=3
TexMipFilter=3
TexCompress=0
TexFlags.UseDither=0
TexFlags.UseAlpha=0
TexFlags.UseIndex=0
TexFlags.PolygonStipple=1
TexFlags.UseClampedSprites=0
TexFlags.DrawLandByTriangles=0
TexFlags.UseVertexArrays=1
TexFlags.DisableAPIExtensions=0
TexFlags.ARBMultitextureExt=1
TexFlags.TexEnvCombineExt=1
TexFlags.SecondaryColorExt=1
TexFlags.VertexArrayExt=1
TexFlags.ClipHintExt=1
TexFlags.UsePaletteExt=1
TexFlags.TexAnisotropicExt=1
TexFlags.TexCompressARBExt=0
TexFlags.TexEnvCombine4NV=1
TexFlags.TexEnvCombineDot3=1
TexFlags.DepthClampNV=1
TexFlags.SeparateSpecular=1
TexFlags.TextureShaderNV=1
HardwareShaders=1
Shadows=2
Specular=2
SpecularLight=2
DiffuseLight=2
DynamicalLights=1
MeshDetail=2
VisibilityDistance=3
Sky=2
Forest=4
LandShading=3
LandDetails=2
LandGeom=3
TexLarge=1
TexLandQual=3
TexLandLarge=1
VideoSetupId=17
Water=4
Effects=1
ForceShaders1x=0
PolygonOffsetFactor=-0.0625
PolygonOffsetUnits=-1.0