Thursday, March 31, 2011

Step the third

OK, so technically the next step is animating, but this isn't an animation tutorial so you go do what you have to. Once you've got your animation done the next thing we've got to do is get things ready to render. So this means lighting and materials. Lighting is about using your eye more than anything else, but if I go through a few of the different lights and what different things do what you should be able to figure it out for yourself.
So I usually just switch to the rendering shelf for this stage, everything we'll need is there.
The first light we're going to talk about is the ambient light, which is especially important in outdoor scenes like this one. You're usually going to want to use at least a bit of ambient light, regardless of the setting, unless you're going for a particularly moody shot. The ambient light gives a pretty even wash over everything so it'll mean you can see pretty much everything.

This is the directional light, which is really good for simulating sunlight. It doesn't have a particular source so it'll just keep going in the direction you point it forever. It's pretty simple but other lights give you a little more control.
The point light is perhaps the most versatile of them all. You could probably light most scenes using nothing but point lights. With a point the light travels in all directions away from the source.
The spot light is useful because you can be very specific about where the light you are creating goes. I find the best way of using a spot light is to look through it (panels>look through selected camera) and you can see exactly where the light will begin and end. Adjust the Penumbra angle to soften (up) or harden (down) where the light ends and dropoff does the same from where it begins.

The final light we're going to talk about is the area light, which emits light from a surface area. This is good for simulating the light that comes from a doorway or a skylight.

There are also volume lights, but they're a bit more complicated so we won't go in to those now.

Right, so for this scene I've created an ambient light and a point light. The set up looks like this
So here the point light is basically simulating the sun. Next we've got to get the colour balance and intensity right. You're going to want to tweak these settings, which you'll find in the attribute editor
So because we're using a setup of more than one light we're definately going to lower the intensity. Also the shot I'm using isn't particularly light, so I've taken the ambient all the way down to 2. Note I haven't altered the colour on the ambient. It's not necessary to do that because we can do that with the point light. You may find, however, in your scene that it is better to alter the colour somewhat in other lights. You might, for example, want to use the slider to make the light closer to grey.
These are the settings on my point light. I've taken the intensity down again. Use the boxes for emit diffuse and emit specular to control how the light reacts with more reflective surfaces. I've also changed the colour to a more orange one. It looks closer to brown here but combined with the ambient light it'll hopefuly look quite close to the light in the scene.

The next thing we're going to do is add the shadows.
So we want the shadows to come from the point light in this case. You have to think about which shadows you need or don't need in your case. The best thing to do is look at your reference and try to mimic that.
Anyway, go to the drop down bars in the attribute editor of the light you're using.
Click "Use Depth Map Shadows"

Now we can tweak a few different things. The resolution is how detailed the shadows are. If you are making something with particularly sharp lighting you'll want to put this up pretty high, but for most cases we can leave it pretty low and make up for it using the filter size to disguise it.
The filter size basically softens up your shadows. For this shot I'm going to put the filter at 3 and up the resolution to 1050. This is what my shot looks like right now close up.
Now I'd say those shadows are a little too dark for the shot we're using here, so we can go up to the shadow colour slider and lower that quite a bit here.
A little better. This part is basically about trial and error. Just keep tweaking till it looks about right.

So the next step is how we stop the blocked out objects from appearing in our render, but still show the shadows.
Basically you need to select all the objects that you don't want to show up. So in this case it'll be the ground plane, and the three polygon cubes that make up the billboard. Then, still under the rendering shelf from before, press the use background tool
Everything should go green. Now when you render they won't show up, but the shadows they create will.
If you want to check the shadows to be sure that they're showing up ok switch to the alpha layer renderer by pressing this button


And now we can see what the alpha layer looks like we can see what will and won't be displayed in AfterEffects. Next we're going to want to take out the image plane we've been using for reference so far. So go to window>rendering editors>hypershade
Then we go to the Cameras tab
click on the image plane (on the left here) and press backspace to delete.

So the final part of this step is to render out your shot ready for compositing.

Near the top you'll find the render settings button
Click that and we can make sure everything is set up right for this.



We're going to render in .tif files. I always have the naming conventions as "name_#.ext" with a frame padding of 3 (the frame padding indicates how long the frame number will be, so frame one with 3 frame padding will be frame 001. So your frame padding would be 4 for 1000 frames. See?)
Make sure you set your end frame so that you don't cut anything off/render too much. Set your camera too. Don't want to be rendering the wrong view. And the image size will be whatever size the footage you're working with is. Mine is 489x320 because I got my footage from youtube. Which is also why it's such good quality.
So under the Maya Software tab just put it on production quality and leave the defaults.

Now we can render! Go render>batch render
If you're having trouble here you may not have the rendering toolbar up, check that here

And come back after that's rendered for the fourth step!

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