Stillmatic hat geschrieben:Had a closer look at the rain effects in cockpit view as I think they both look great, and I was curious to see a comparison. They're done quite differently with some big differences.
I've tried to keep the .gif file sizes down, but if you're on mobile you might want to wait until the next page before revisiting. :p
Please post if I've overlooked something, got something wrong or you know more about these things on a technical level (I know little).
Neither seem to be going for photo realism, they're both exaggerated/stylized.
- It looks like DC has a fully dynamic fluid system that handles the whole rain simulation on the windscreen.
- It looks like FM6 uses dynamic multi layered textures and blend masks to bring it all together.
FM6 left, DC right:
- In Forza the drops don't merge to become larger, the drop masks the other drops out.
- In DC, each drop can merge with each other. Here you see a rain drop landing beside another and them merging and becoming larger. It's now influenced by force more and travels faster along the windscreen.
FM6 left 3, DC right 2. (Left and right wipers of the same footage, just cut side by side to save .gif size. The middle .gif is the right FM6 wiper coming back down):
- FM6 isn't picking up the drops along the way as it's a layered effect, they're being masked out, then turning on the pool of dynamic drops at the end of the wipe.
- DC is running a fluid simulation, so each drop is getting picked up by the wiper and then merges with other drops. If these drops don't run off the side by the next wipe then they get added to the new batch of drops. Which is why you sometimes get a shitload of water (jelly effect) on your screen:
Because of that last point DC can gets large amounts of water on screen, looking awesome but over the top if you want realism:
Side windows - FM6 left, DC right:
- FM6 use the same technique as the windscreen, large drop movement is dynamic and moves with the forces of the car.
- DC is using a layered textures/sliding textures here, which is not dynamic.
FM6 left 2, DC right:
- It's a bit harder to see here but in FM6 the smaller drops aren't dynamic, as in they don't move. Only the larger drops are effected by force and direction. What FM6 does well here is show the water dissipating, it's done by fading out the layer (shown below). Water only does that from a lot of force at high speed, but it looks neat here.
- In DC every drop is effected by force/direction. It's subtle in DC, if a drop is individual it isn't effected as much but still move along the screen, when 2 or more drops combine you see a lot more movement. The water doesn't dissipate, it stays on screen until it's wiped or blown off.
Here you can see some of the masking and fading in FM6:
I love this effect in FM6:
The drop movement is obviously exaggerated but looks amazing. There should be more weight in the drops resulting in a lot less movement. But what I like (DC does this too) is how the water from the previous right wipe travels across leaving streaks to the left side of the screen and is then caught by the left wiper (this is looking at the top half of the middle part of the screen). But it looks better here in FM6 due to the fogging of the window, something DC lacks.
Here's more on the point of weight: FM6 left, DC right:
Both cars are idle, water from the wipers in FM6 are treated with no weight/surface tension, it travels off to the side at a constant rate. In DC the drops are effected by gravity/surface tension and slide downward.
I think the variation in drop sizes is a lot more realistic in FM6, but they look like flat textures. DC is the opposite, large drops mostly but have depth:
At times the weather effects in FM6 can look a bit odd/disjointed, but when it all comes together correctly the weather effects can look fantastic:
In terms of lighting and reflections, DC accurately reflects the environment and light sources. I'm guessing it uses some form of GI, as the rain drops reflects the light bounce of opponents car paint and environment around the track.
Here on the right side you see the yellow light illuminate the drops on that side of the screen. Then towards the end of the .gif you see on the left side, drops light up red from break lights, yellow from side banners and blue from the car in front.
I haven't seen any FM6 rain footage at night to compare. But I don't think they react to light in the same way going off overcast footage. Probably due to using cube maps?
Which you prefer the look of is a personal choice. The way DC
simulates water on the windscreen is unique and hopefully the direction these effects will go in the future. There's room for improvement but it's incredibly impressive in its current state:
Und Drice Club gseht scho no än Tigg besser us.. bis uf dä Räge.. dä isch mr jetzt chli too much
är hät a halbi Wägelängi gwunne gha
