Compositing & Network Animation Test

[J_Bug]

I've been learning multi-pass compositing of VRay animations in Combustion as well as working with a render farm lately. The image below is a quick Photoshop comp of background, foreground and foreground shadow layers. I know it's a simple setup but it's for learning purposes. The animation is short also but for the same reasons.

So what do ya'll think about these test renders before I up the settings and send the passes off for rendering?




http://www.dtoxx.com/J_Bug/Cat_02.avi
Please right click and save to conserve the servers bandwidth.

Thanks,
--Jon

[Da_elf]

can you post the photoshop document as well?

[J_Bug]

I'd prefer not to post files that large and/or if they are source for more than just a basic helpful test. Hope you understand

The setup in Photoshop goes like this (first is top layer)...

(Normal w/Alpha) Cat rendered with invisible environment objects for glossy reflections.

(Multiply) Foreground cat shadow across a few matte objects (base of pillar and floor). I've learned to do this with a black background but this only produces black shadows. I've rendered with a white background and use the Multiply transfer mode so that I get color in my shadows.

(Normal) Background room Rendered with saved irrad map.

So what do you think about the scene in general?

--Jon

[natty]

i think it's great J_Bug
Compositing is something i need to learn more about and is something that has always been a little confusing for me .. perhaps if you had the time you could do a simple tutorial ? :P

[Da_elf]

no offence to j-bug but it would be awsome to see a full tut by richard
although i know he is a busy man hehe

[J_Bug]

Da_Elf:
I agree with you but Richard Rosenman does have a great little animation which touches the surface just enough:
http://www.richardrosenman.com/coverna.htm
check out the making of vid.

Natty: Thanks but I don't think I could write a better tut than Seraph:
http://www.seraph3d.com/composite_main.htm
Maybe when I get a little better at it's intricacies I'll have something to compile... maybe :P

--Jon

[Seraph135]

Looks pretty good J-Bug!

Doing the shadow pass the way you did is probably necessary for compositing in photoshop. If your compositing in Combustion or Fusion you don't have to do that to get colored shadows.

I like the cat. The columns and floor look a little plain right now though. You might add some extra details if you have time. Overall it looks good though.

[zuliban]

j bug did you model and textured the dog(anubis)?? coz is pretty cool

[Arkitec]

isnt it an egyptian cat?

Arkitec

[Syclone1]

my guess would be a cat also

great work anyway

-dave

[J_Bug]

Hey thanks all,

Seraph: Hey thanks, I'll have to look into it when I get them into Combustion and please correct me if I'm wrong but I don't quite see exactly what your saying. Using the method in your example I get a black image with alpha as you described and I could do the background color tint to colorize (which is great for single color light sources.. If you see my shadows are basically two colors though. The method I'm using with the white bg and multiplying in comp software saves the color range. Are you saying that this won't work the same in combustion? I'm a newby with Combustion but as I'm learning it seams I can do almost anything that's possible in Photoshop
I think your right about the environment. Just haven’t taken the time to come up with any nice maps (Lazy ). Other than the hieroglyphs it's all procedural now.

Zuliban: Doesn’t at least the tail give it away It's a cat but with a few FFDs it could make a decent Anubis too I did model it and the materials are all VRayMat and procedural maps. It's kinda mismatched with the environment though. The background is meant to look ancient Egyptian (and somewhat new, in it's period) but the statue is more like something you buy in our modern time. In ancient time the stature would look much different, made of bronze most likely and attached to a huge base. Well it's just for learning purposes right now

I've also got a question if anyone can help. Lately I've been getting the smallest amount of noise from camera moves. I have the QMC Sampler set locked to pixel and AA appears to be sufficient but I still get this crawling noise. I hope you can see what I'm talking about in this DivX compressed version of this first bg plate along with some settings that may be pertinent. Anyone else run into anything like this?

http://www.dtoxx.com/J_Bug/CatBGSet.jpg
http://www.dtoxx.com/J_Bug/CatBG_02.avi

Thanks much for the c&c,
--Jon

[Seraph135]

Are you saying that this won't work the same in combustion?

No, I wasn't saying it wouldn't work. If you follow the same procedure you did with photoshop it should work the same way in Combustion. I was merely saying that you don't NEED to render like that in order to get a shadow in Combustion. I'm actually a little confused about your comment about different color shadows. Could you explain a little bit more about how you've set up your shadow pass and what your doing with it in photoshop?

[J_Bug]

I haven't had a chance to run it in Combustion yet but I see what you're saying...

So basically there are two primary lights for the subject, the key being an orange torch and the back light a blue area like a doorway with skylight soaking through and here's a break down of my PS file:



See what I'm talking about with the shadows and the white background color is what gives me this to multiply over my background sequence.

Before I started rendering multiple passes and comping them I was aware that it was done but I always thought that alpha channels were the primary means of layering animations together. I've done quite a bit Photoshop work for years but I didn't realize that the same methods were used for animation sequences. I hope I'm not missing something and sticking my foot in my own mouth

Thanks again for the great set of tuts They are one of the reasons for this great revelation

Any ideas about the noise problem. All I can think is that it must be the fine bump I'm using but with my sampling set to Adaptive -1,4 and the blurring type AA filter soften I thought this could be avoided.

Thanks,
--Jon

[Seraph135]

Well...I did some tests and I think you got lucky this time. It turns out that multiplying in photoshop and multiplying in Digital Fusion do not give the same results. So you should try your shadow pass in Combustion to see if it works the same.

There isn't really a right or wrong way to composite something. As long as you get the results you want thats all that matters. That said, I think the multipling shadow pass idea is maybe not going to be the best option for all your future projects. The problem with it is that it limits your options as to how much control you then have over their color and opacity. You also can't edit each shadows color separately without re-rendering.

For example. If your client for some reason up and decided that he wanted the shadows to be white (don't know why, but clients can be strange sometimes). Multiplying is no longer an option. You would have to create an all white pass with the shadow in the alpha and drop that on top with a normal blend mode. So the question is why not just set up your shadows that way in the first place? You can make them any color from white to black that you want at anytime without re-rendering. And you'll still have the option to multiply the shadow color over the background if you want.

The problem is that if you want two different colored shadows you will need to have two separate shadow passes. It gets a little more tricky though. Your cat is very dark so you don't notice that around his base he isn't getting darker like he would in a GI render (try making him grey and you'll see what I mean). Your shadow pass has a sort of built in GI happening to the shadows only cause where the cat is occluding the light it becomes black. When you multiply that over the background its still black. However, if you render your shadow pass using the method in my tutorial your shadows will be a just a solid color. To get the same end result that you almost have (cause the cat is black) you need to also render an ambient occlusion pass which you multiply over the whole scene. This will give your shadows the same appearance as your multiplied version.

As I said before, there isn't a right or wrong way to comp something, but I tend to think that its worth rendering an extra pass or two if it gives you a nearly unlimited amount of control in the end.

I hope this helps. Let me know if your unclear about something and I'll do my best to explain.

[J_Bug]

Yeah, the primary reason for multi-pass is for flexibility and your solution does give the ultimate. I think I get the general idea of what you're saying. I'll check in Combustion when I get to a stopping point in rendering at home. I've found a few things in Combustion that don't quite make sense to me, with my Photoshop mind set. There's one feature I've found called replace which has saved me hours and I'm still not sure exactly how it works.

Extremely helpful , thanks much
--Jon