Thursday, September 25, 2008

Hydrant in Nuke

Well, my hydrant is about 90% rendered and I was really getting impatient to get onto compositing. So I decided to just give it a try to whatever I had so far. But instead of using Fusion, I decided to try Nuke this time and see how different or how similar it was to Fusion.

Well I guess I did have fun using this program. Just that I find pulling the wires out of the nodes to be a little troublesome as compared to that in Fusion. Also, Fusion has this drag and drop function regarding the nodes to display in the view. In Nuke, I would have to pull a wire from the viewer to a node everytime I want to preview it. Definitely troublesome, but I guess I would get used to it.

I did not follow any tutorial on how to composite in Nuke. Based on my knowledge of Fusion, I composited the several CG passes and got what I wanted. Below you can see the node graph. It would have been similar to that of Fusion.

I'm still extremely new to this program, so I couldn't quite figure out how to get my z-depth pass as a Z channel integrated with the rgba channels. In Fusion, I would have to make use of the channel boolean tool. In Nuke, I tried using channel merge but it didn't quite give me the results I wanted. Color correcting was also quite tricky and complicated. But I kind of figured out my way to get the result I wanted.

Overall, I was quite happy with the result. It's still incomplete though - I still have to match the grain of the raw plate, adjust my reflections and specular highlights, etc. But I would polish it up once my render has finished. Currently, about 100 frames or so left to render from the reflection pass.

Wednesday, September 24, 2008

Mini VFX Project

It's been quite a while since I last posted, and I'll tell you why. My hydrant renders kept failing as I mentioned earlier. But I found a way to solve things. I realised that my laptop got heated excessively inside, thus it shut off on its own. So what I did was put it on top of a book, so that there is more space at the bottom of the laptop for the heat to escape. Then I took a few wet cloths and placed it on the hottest part on my laptops to cool down the laptop. Funny thing you might say, but it actually worked! My renders carried on, although at a very slow speed. The diffuse, specular, shadow and occlusion passes are all rendered. The only one left is the reflection pass, which is less than a quarter way done. I added a new pass - z-depth / luminace pass so that I would have more control over the depth of field during compositing, although its just one object.

Moving on, I haven't had time to do much work because of the rendering. But, Greg and I decided to do this mini visual effects sequence. The entire point of doing this short project is to firstly test out all the vfx techniques we both know or want to explore, such as matte paintings, 3D integration, matchmoving, minitature shooting against green screen, etc. Secondly, we want to see how it is like to work on a visual effects sequence in a pair. After all, teamwork is what the industry wants.

So we got started. Using the resources we had, we came up with a simple plan of the vfx sequence. In this case, Greg had this toy Hercules plane which looked pretty realistic from certain angles. So we decided to base the project around it. Greg came up with the storyboards, and we further developed it. During one of the recent meetings, we decided to have a shot of the plane taxing on the runway before take off. Thus we decided to actual create the foreground minitature set shot against a blue screen. But all this would be at a later stage.

Thus for now, I decided to do a moodboard to have a look and feel of the sequence. I took a snap of the plane from my handphone camera and brought it into Fusion. I took out the background by rotoscoping the plane out and cropped the image to a HD 720p look.

Next, using about 8 paint nodes, I painted out unnecessary things that gave the realism away such as the red sticker, some dents and cuts, the guns in the foreground, etc. Below, you can compare the before and after shot of the paint work.

Next, I color corrected the plane. I wanted it to be mid-air at night, so I wanted this bluish hue. Of course from the way the photo was taken, the highlight was pretty big and the shadows pretty harsh, thus nothing much could be done with that. Hence, I used a couple of color correction nodes to get the desired effect.

Now that the foreground element was finished, I had to take care of the background - the sky. I used the clouds 3D plugin from speedSix and created a night sky by positioning the perspective to match to that of my aircraft image.

Next, to add a bit of realism, I added lights to the windows. However, Greg told me that combat planes do not have such bright lights or any lights at all for it would give away its position to the enemy. So in the final shot, we may not have lights after all. But I just created them for the sake of realism.

Finally, I added forground clouds to add that element of depth.

And this is what the final moodboard image looks like:

Of course this is not 100% complete because of a few missing elements such as consistency - if there are lights on the windows, there should be lights in the cockpit as well. The propellors aren't done up properly also.

I could have used Photoshop to create this entire image and get the same results. But I chose not to because eventually for compositing, I would be using Fusion. By doing this moodboard, I realised the technical challenge that I would be facing when doing the real composite. Also, I'm so used to the node-based way of compositing that I'm starting to drift away from layer-based compositing. For example, the paint operation - it's much easier to classify different paint operators as different nodes rather than have them all on a single layer in Photoshop and not being able to edit once out of the paint mode. Or I maybe wrong. But Fusion will still be my choice.

Thursday, September 11, 2008

Sky Replacement

Update on my hydrant render - bad! Very bad! Desktop too slow to handle, and laptop keeps crashing. Have to find a way to fix this soon.

So meanwhile, I decided to do something else. I was walking home from school and I came across this big patch of grass with buildings in the background. It looked pretty interesting to me, so I took out my handphone and took a video of the place. Just a simple plan. I had no idea what I would do with it. This is what it looks like:

When I reached home, I transfered the footage to my laptop and analysed it - the quality was horrible, it looked totally flat and the sky was siply blow out with zero cloud detail. That gave me an idea - why not colour correct the shot, key out the sky and replace it with a better one? I proceeded, and I gave it a very dramatic mood, as if it was about to rain. I also found a sky photograph which I had taken earlier, and colour corrected it to match the footage.

Clouds Image

Color Corrected Clouds

Then, I realised that the camera was constantly moving throughout the shot and thus the sky image had to follow it. I wasn't familiar with Fusion's tracking tool thus I imported the original footage into boujou and tracked it there. This way, I would get accurate 3D camera information. I imported the tracked camera as a Maya camera file and imported that into Fusion. I then placed the clouds in 3D space, duplicated them and positioned and rotated them to form a kind of a panorama.

That was the final step in terms of 3D compositing. I cropped the shot to a widescreen one and rendered it out with motion blur enabled.

A very interesting practice with Fusion's color correction and 3D compositing tools. On that excuse, I got to use boujou as well =)

Wednesday, September 10, 2008

Cool Compositing Book

Well, my hydrant is supposed to be rendering at the moment, BUT, my laptop crashed and shut down while still rendering the 11th frame of the ground occlusion pass. And there are a total of 162 frames per pass, with a total of 7 passes to render. And it's not that I did not try to render again - I did 5 times and the same thing happened. Well, frustrating no doubt, but I think I'll have to reformat my laptop and render the frames on my desktop. Oh well, it happens.

So I thought that meanwhile, I would share about a book which I borrowed from the library - The Art and Science of Digital Compositing.

This is one of the best books I've read so far - a must for anyone who's interested in compositing. I am just halfway through my third chapter and I'm already learning so much. Not to forget that there real world examples of how certain shots from certain movies were composited. Very cool.

I was exploring the DVD that came with it and I found out that they had actually included a few source files from certain movies. I took the source files from King Kong and did a small composite in Fusion:

The pass breakdown for Kong and the T-Rex wasn't provided - only the beauty pass for each was provided. So I had to make do with that. Nothing great actually, but I got to practice the Ultra-Keyer tool in Fusion to remove the blue screen. Very cool!

Tuesday, September 9, 2008

Hydrant Rendering

This evening I told myself that I should not procrastinate and decided to get the hydrant rendering done.

I started lighting the scene and found this to be really challenging. The lights had to match to that of the actual scene. I added an area light as my main keylight, something which represented the sunlight. I know in most cases, a directional light is usually used for a sunlight. But I guess in this case, an area light suited the best because of the way the shadows were soft during render time. I then added a point light behind the hydrant, somewhere inside the building as my back light and finally another point light as my fill light. This is what the rendered scene looks like:

And this is what the light set-up looks like:

Of course things such as ambient occlusion and things like that will be done during the compositing stage. Right now, I only focused on getting the lighting almost accurate. Next, I went onto creating the render layers. I added two layers for occulusion - one for ground occlusion and another for the hydrant occlusion. I did this so that I could control each occlusion pass separately during compositing instead of masking and rotoscoping. Next, I added the usual diffuse and specular render layers. For the reflection layer, I used a phong shader as a material overide for the hydrant and made it super-reflective so that I could reduce and control it during compositing. For the shadow layer, I used a background shader as a material overide instead of the default shadow preset. This gave me more control over how my shadow looked like.

Once the render layers were set up, I did final touch-ups such as naming each pass, turning on final gather and ensuring that every pass was being rendered as high quality through mental ray. Currently, all the passes are being rendered.

The compositing will be done in Digital Fusion. I know I mentioned in my previous post that I would composite in Combustion as well and try to get similar results from both the packages. Well, I'll try to do that but Fusion would be my first choice.

Saturday, September 6, 2008

First Works using RenderMan

I was just looking through my old works and I came across these two images which I totally forgot about. I used RenderMan to create these images. The first one, I used Slim to generate a glass shader. I decided to go the extreme and increased the refractive index to a very very high level. I rendered the image in Maya through RenderMan of course, and this is what it looks like.

For the second image below, it required more work. That time, I was really into RenderMan and the RenderMan Shading Language (RSL) and I did proper research on it. Well, I didn't exactly copied the RSL code, but I learnt and memorised it and wrote the anistropic shader in my own way for the following container which I modelled in Maya.

One thing about RenderMan - extremely steep learning curve. I guess one requires good mathematics background to master RenderMan, which I currently lack. So I decided to put it aside for the time being, and decided to concentrate on visual effects and compositing instead for the time being. Once I have mastered that, I want to explore advanced CG lighting using mental Ray and RenderMan and really go into its depth and then use that knowledge to create some good VFX.


Okay, nothing new about my works so far. I've done something for my school project. Wish I could post it up here, but I can't as yet. Have to go through some paperwork first.

But anyway, I read a lot about Digital Domain's in-house compositing software, Nuke. There were a lot of debates on whether which one is a better choice when compared to Fusion. Well, I decided to give it a try on my own without consulting any kind of tutorial:

My take on it - the workflow is almost the same as Fusion when it comes to basic CG multipass compositing. Simple mathematical operators and a few merges and there you have your composite. I used the same old files to try this composite and I did a bit of colour correction. Well, this was the tough part. The colour correcting nodes are so complicated, that I couldn't quite understand. For now, I would still stick to Fusion because I'm starting to get very familiar with it. But I would still learn Nuke since it's industry standard.

Well, that's my take on it. Very short post. More later =)

Wednesday, September 3, 2008

Flickering of Trees - Fixed

I finally managed to fix the flickering of the trees in Fusion. I had to keyframe a few values to stop the flickering. I re-animated the camera, but I don't quite like the result. Still prefer the previous camera move. Another addition to this animation is the animation of the clouds - its animated using the same technique of grid warp.

This animation was rendered with a hell lot of motion blur, so the rendering time was really expensive - 8 hours! Oh well. Enjoy.

Tuesday, September 2, 2008

Dramatic Sunset + Rain

Okay, it's been quite some time since I posted an entry. I'm so busy currently because I have so many projects at hand - both from school and personal. And most of these projects revolves around Fusion =D

So a very brief and quick post for today. One of the projects I'm working on is a dramatic sunset which transforms into a night sky, after which it starts to rain. It's part of a logo animation for Crewsade I'm doing. And a good thing is that the techniques used are all discovered by myself while exploring Fusion. So what I did was I started off with a simple static jpeg photograph of clouds which I took from my handphone camera.

I animated it using two grid warp nodes - one to animate the background clouds and the other to animate the big foreground cloud. Then I went onto color correcting this animation - one to make it into a warm sunset evening and the other into a night scene. I also created the sun, added the light rays and a lens flare.

Sunset Scene

Night scene

And I went onto add the subtle lightning happening behind the clouds using color correction and a mask.

Can't really see a difference here but in the animation, the lightning is very obvious.

Once these three passes were done, I merged them all. I animated the sun setting and the light rays to follow it. The scene changes here gradually into the night time scene, lightning strikes and then it starts to rain almost immediately after that. This has been the most complex work I've done so far:

One thing I learnt from this mini project - be organised when compositing. Keep the nodes nice and organised so that the entire flow is easy to read.

Unfortunately, I haven't rendered the animation yet because it takes a hell of a long time to render with motion blur and the fact that it's in high definition. I'm currently busy with a school project (which I can't talk about right now). Once I'm done, I'll probably render and upload this short animation.

More later! =)