There is a problem that the texture is not fully displayed

[somtydw]

As shown in the figure, in some places all the textures can be displayed normally, but in some places only a part of them can be displayed.

[michael_nikelsky]

@somtydw 
On first glance it looks like you have set a projection depth for a planar projection in the material and the parts that are cut away are outside of the projection range. Try to set the z-axis for the projection size to 0 or a larger value, depending on what you want.

[seiferp · Accepted solution]

@somtydw 
The decals have a virtual thickness (yellow bounding box) of 20mm. A value of 0 makes the projection infinite. In your case you can also move the decal a bit on z-axis and if this causes issues in other areas make the box thicker on z.