Physical Sky - Weather System (Prototype)

[janpec]

@;477338

Thank you all!

I plan to release two versions. One without AI (maybe some basic dependencies will be included) that will obviously be available earlier.
And one with AI and real world weather data.

As to where and when: I aim to finish the version without AI until the end of summer as a full featured plugin. And hopefully it will be on the UE4 Marketplace.

My goal is to have a solid system that works for every kind of product and art style. It will be at least as realistic as it is now when it’s beeing released. If thats not enough for you the system will have many ways for you to further improve on that.

The snow buildup in the video is entirely made with vertex displacement on the landscape. I started it with tesselation but that was way too performance heavy (around 30fps drop).
By using regular vertex position offset I noticed a drop of max 5fps.

To find there areas where to buildup the snow I used the distance field in the landscape material (the landscape has no distance field representation to not necessary to exclude that).
This method is 100% realtime so if you move the sphere the buildup would move with it. In Snow V2 you will be able to edit that buildup with extra vertex paint or landscape blend layers.

The thing that has the heaviest impact on performance are the clouds. They produce super heavy overdraw and I’ve found no way to say: stop when alpha has reached 1.
So depending on whether you look directly at them or not the cost ranges from 30fps to 50fps. I will not try to find out the exact costs in ms as they are so high that it does’nt make sense.

Regarding the performance: Nothing is optimized (thats the reason I am doing a full rebuild).
I just made it so it will run decent on my system for now. Decent meaning at least 40fps on a dev build in fullscreen.

For reference purposes:
i7 4790k @ 4GHz
32GB DDR3 RAM
GTX 980 4GB

Thanks for answering, too bad that performance requirements are so heavy, but still non the less it does look very nice.