As far as I can tell, the TOS has no prohibition against informational links off site, except when those links lead to sexually explicit material, which is forbidden. 

"Commercial images are welcome in the galleries with following restrictions: 1. Posting of commercial images/links is limited to active vendors and products in the Renderosity Marketplace."

That paragraph on commercial images in the galleries does mention links, but qualifies the statement as being regarding only the galleries. It seems to be a prohibition against advertising. The links in this thread are not promotional advertising, nor are they in the gallery, so that paragraph doesn't apply.

Finally, a paragraph disavows responsibility for content reachable from member-supplied links, which is tacit approval of their existence.

"Off-Site Links: The Renderosity community contains links to a variety of other web sites. These are usually in the form of member/user provided links. Renderosity cannot, and will not be held responsible for the privacy practices, or content of any web site other than our own."

I can't find any other mention of links besides those three. What rule are you referring to?

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Renderosity forum reply notifications are wonky. If I read a follow-up in a thread, but I don't myself reply, then notifications no longer happen AT ALL on that thread. So if I seem to be ignoring a question, that's why. (Updated September 23, 2019)