Depends on the license that came with those textures. Read the License for your software, it'll probably say something in there about the pre-built stuff that comes with the software.
I believe John Whelan was referring to use by N3V in payware they may offer in the future. You can't prohibit that because the terms of use of the DLS include consent by you to this use of your uploads by N3V.
If you want to be perfectly safe, find a contact email for the provider of your program and send them an email asking for restrictions on use.