This time, I think I have really pushed my Amiga 68040 with Lightwave 5.0 to the limit, as described below.
Creating this image was incredibly complicated due to the computing power that the good old Commodore Amiga struggles to provide in this latest work of mine. In fact, I completed the entire project using Lightwave and Modeler on this powerful computer of yesteryears... However, during the rendering phase, I realized that on the real platform, it would have taken at least a week to complete the calculations. Even after a whole day, the first pass of the 17 levels of antialiasing was not finished!
This was because I added transparency for the glass window along with refraction effects. Moreover, to achieve the wet effect, the surface is not flat but wavy at a 'micrometric' level. In addition to the raindrops on the glass, I provided the same transparency characteristics, which meant countless calculations for each raindrop involving refraction and reflection, significantly lengthening the rendering time. During various tests, all conducted on Amiga, I disabled all unnecessary elements, working at a very low resolution of 100x80 pixels (I can hardly see anything!). I used the Blur effect to achieve the visual 'uncertainty' that only rain can provide. In the foreground, to depict a heavy downpour, I used 'extruded elongated particles' in motion, accompanied by a motion blur effect. Thus, I used features provided by some animation frame settings, and the rendering process began from frame number one, not zero! Consequently, the final rendering was performed on WinUAE, taking a substantial 7 hours and 17 minutes on a modern processor.

Nevertheless, I also wanted to recreate a rendering on a real computer with minimal antialiasing details and a resolution of 640x512 pixels, just like it was done during the heyday of Amiga and as everyone did with their works during that period on 486 and Pentium I computers, and of course, on Amiga... This rendering was completed in 23 hours and 51 minutes, and you can see it on this page (the result is still very good), and the download link is provided below.

CONTEXT:
I love the rain; often, I gaze at the landscape during rainfall for the colors it presents. I find that the greys evoke contemplative thoughts. I enjoy going for a run when it's raining because there's nobody around, and I feel like the master of all the places I pass through. When I am at home and see a downpour, and perhaps I am engrossed in studying, I occasionally take a few minutes to look at the panorama from the second floor of my house through the wet glass, and it looks like a painting full of distant details. That tranquility takes away the stress. Sometimes, my hand leans against the glass, almost instinctively wanting to touch something on the other side...

Here you can download the image directly calculated on Amiga in IFF format (640x512) and compressed in ZIP:  DOWNLOAD

Final result of the image rendered on Real Amiga (A1200 Micronik 68040) in 640x512 pixel format and displayed with ArtEffect 4.

Capture of the scene in Lightwave 5.0 on Commodore Amiga.