[cgh]

PKD had amphetamine problems, not methamphetamine. Though of course they are related, meth is in a different class when it comes to potency. His hallucinations and mental issues started well after he finished a drug rehab program in Vancouver so it's not certain they are related.

As an aside, the dreary, rainy atmosphere of Blade Runner was inspired by Dick's residency in Vancouver.

[colordrops]

Was he involved in the making of the movie? Or were the dreary and rainy scenes described in detail in the book?

[singlow]

He was not really involved. He was consulted a bit, and while he disapproved of the original script, it seems he liked the rewrite. He screened a preview and reacted positively to the general feel, however he died before it was completed.

[cgh]

I doubt he was involved. I believe he died only months before the movie’s release. The story/novella describes plenty of grim weather because Earth’s atmosphere has been nearly destroyed.