Depth Bias Alpha and Plans

So now that I've effectively finished with uni I can finally take the time to get back into doing what I love. So I took some time to sit down and try and learn how to make my own depth bias alpha as it's something I end up using a lot in my FX and it's just so expensive. The base of this is from a section in Bill Kladis' recent tutorial. But I modified it to work directly in cascade as well as using some of the techniques from Uncharted 3's excellent FX presentation.

Above is just a simple test emitter with a simple circle sprite. As you can see where it intersects with the geometry it creates a hard edge.

Using a simple scene depth and pixel depth equation I was able to smooth out the edge. But I linked the control with a dynamic parameter so that I may control the softness of the intersection  directly in cascade.

Then using the idea behind the fire techniques in Uncharted 3 I was able to run a couple of gradients through the scene depth before it had the pixel depth subtracted from it. This breaks up the straight edge of the intersection to make it more natural and varied. This is great for effects such as fire, which is what I ended up trying it with. Again I can control the amount of noise with a power node connected to a dynamic parameter so I can control it on the fly in cascade.

Here you can see the material. It's still not exactly cheap so I have to be wary of how many particles I spawn but considering a normal depth bias alpha node generally pushes my materials above 50 instructions it's certainly much cheaper. And I could make it cheaper still, if it's just a smoke or any normal material that needs it I could remove the gradient stuff.  

And here is how it looks on a really basic fire emitter. But now I've learnt the basics of how it works I can start implementing this in my pipeline and decrease the instruction counts of my materials.

But now that this little experiment is over I should start thinking about what I'll be working on next. Now I've got the time to start working on my show reel properly, and not a rush job in a week for deadlines. I think that I've got a good starting point for one; I might render out my rain shader properly by itself as a break down of the street scene. I think I need to almost start from scratch with the gas station explosion and redo it. I can take this as an opportunity to really get to grips with Maya Fluids and improve on my skills using fluid sims. As for that spell effect, that just needs to go, it's just weak. But I think that if I worked just a bit more on the beam that I could get that to be a really nice effect.

Showreel

00:00-00:36 - Alleyway Environment. I worked on all the environmental FX in the scene including all particle emitters and rain shader in UDK. All assets made by me as well.

00:37-01:00 - Gas station explosion. I made all the emitters and textures. Flipbook textures made in Maya using Maya Fluids and After Effects. In UDK.

01:01-01:30 -  Energy beam. I made all textures and emitters. In UDK.

Updates and Stuff

Here's a brief update on my gas station scene. I've not done much to it since the last time I updated. The only major change I've made is redoing the smoke plume after the second explosion. The rest is mainly just tweaking.

In other news, I've also finished up the majority of the work for my final major project at uni. It's so nice to have this finally in it's finishing stages. Not only did I learn a lot from this project but it's nice to have to finished so that I can be free to move onto other projects. 

Fire Tests

So I've been playing around with the smoke plume recently trying to get it just to look a little nicer. I was trying to implement fake lit particles as I've not worked with them before and I thought it would be a good place to try and get to grips with it. I also experimented using macro UVs. 

I really like the aesthetic of the one on the right, I think it also has much more fidelity. Unfortunately it's also far more expensive. So dat next-gen, huh? No, I definitely think that if I do want to use it for my final renders I'll definitely have to go in and strip it down to make it game ready. 

Blue or Orange??

I finally managed to figure out why UDK kept spawning the emitters twice. Months of trying to figure out what was wrong then you watch one tutorial and find out that it was just one measly check box. This happens too much in UDK. But now I can finally render out videos properly so it's all good.

So here's the ground attack again but now rendered properly. And below is the same effect but with just a different colour palette. Looking through my blog again I realised that I veer too easily to the blue spectrum and that maybe I should try using a different colour scheme once in a while. 

So I should be done with this one, for good now. But I might just quickly build a nicer environment to render it out properly just to look nice. But other than that I can get on with other things now.

Ground Attack Updates

So I got round to finishing this off over the weekend, kind of. I saw kind of because I've not done a final render for it I'm still using the level I was using to test it. I really should get round to building a nice render scene that I can use for most of my effects. 

Anyway, it looks a little different to how it was before because I got so frustrated with it not going the way I wanted and ended up completely redoing it but it all worked out for the better. The reason there are two videos for this is because I was not really sold on the dust streaks in the middle so I tried a render without them in to which I feel is a little lacking so I think I'll keep them.

And again I apologise for UDK's stupid rendering system, I've no idea why it insists on rendering every emitter twice with a fraction of a second delay. Every render I have ever done has done this so I'm not sure whether it's something I'm doing but I'll definitely get it fixed for proper renders.

As for now, I have to figure out why UDK's rendering emitters twice. But other than that I'm going to start trying to teach myself Maya this week as I feel I need to get to grips with it as it's very useful for an FX artist for both it's fluid dynamics and it's cloth simulations among other things.

Explosions and Other Stuff

So I'm still working away on the explosion as well as a bunch of other stuff. Getting close to deadlines for uni projects so I'm trying to balance my time effectively between that and other projects. But I just thought I'd do an update of what I've done to the explosion.

So I started to block out the second explosion. I'm trying to go for something much larger in scale than the initial explosion to give it that more variety but more to show that it's building up to something. Like I said, I've only really blocked it out at the moment so there are still some issues with the timing. And the biggest issue I've found is how to naturally blend between the roaring fire and the explosion, but it's all still very much WIP.

I've also whipped up a quick concept for the next thing I want to work on.

So basically the idea is that it'll start off as a small ball of energy that then starts gathering the energy around it. And as it starts to increase in size and take in more energy it'll become volatile and vibrate violently before exploding in a beam of energy. I think for the beam I'll try working with some mesh particles to get the overall shape down and probably work with some beam particles for the centre. I've never actually tried working with beam data so it's a good excuse to learn it. I think I might add some dust particles that shout out backwards at the initial release of energy to try and give it some nice counter motion.