Pre-2005 world-jumping sci-fi with giant trees?

[Willy]

Can somebody help me find the name of a sci-fi novel I read around 20 years ago? (It could be significantly older)

I don't remember the plot much at all but it involved a laboratory where they ultimately transport a huge sphere of wood from another dimension (or world?) They were messing around with some technology that was unexpectedly creating smaller spheres of odd materials. It's later revealed that they're swapping these coordinates between the worlds and it just so happens that the coordinates that match the lab in this other world are in the center of a very large tree.
When the giant sphere transfer happens the people & parts of the lab end up in the center of a tree & they have to cut their way out to get out to the open air. Outside there are birds (or something) that poop rainbow colors to mark out their territory and the main character has a nightmare about brushing away all the markings and starting a fight between the birds.
Hope that's enough to get things going.

[David]

Hi, Willy

Do you remember anything about the cover?

[Willy]

I posted this on twitter too and someone suggested 'Twistor' by John G Cramer. I think it's probably correct, but my snippets of memory of the book aren't in the synopses I've found. Now I just have to dig into my library to see if I have a copy!
https://www.goodreads.com/book/show/1...

[David]

You can read it on the Internet Archive. Need to be a member, but only require an email address to sign up

https://archive.org/details/twistorcr...

Twistor by John G. Cramer for the trackable link.

Also, sometimes I think GR search engine is too smart for its own good. If I'm searching for "Twistor", I shouldn't be offered 77 pages of variations of "twisted" or "twist" before giving me the exact match in page 78.

[Banjomike]

The rainbow bird poop is certainly in Twistor.

[Kris]

Google Books preview of Twistor by John G. Cramer:

https://books.google.com/books?id=06j... There are different cover images.

Quotes from the book:
- Then it sorta did a waddle dance along the line, and I noticed that it was making poop on the ground. David, it can poop in colors!" David looked at Jeff, then speculatively up the tree. He could see the green treebird at ...
- "The wood sphere is not from any tree growing on Earth, but nevertheless its basic biochemistry is also identical."