Subtitles of the Movie

In this project I have a 3D scene with a pyramid I built out of 2D shapes. The pyramid is piercing another shape that's a circle object here and I'll orbit around it a bit. I've guilt this little science project to demonstrate a specific type of rasterize; 3D rasterization. We know from previous lessons that certain things can trigger 2D rasterization, like a group's drop shadow parameter, blend modes other than pass through and some filters. We know that 2d rasterization simply means that a group is turned into a single bitmap graphic which means that it no longer calculates the layers beneath it in its 2d stack the same way. In 3D, rasterization is a little bit different. Let's pick the green circle. Changing the parent's blend mode to anything but pass through rasterizes the green circle. Look in the Layers Tab and there's the box around the group's icon which indicates that it has been rasterized. What this means in a 3D scene with 3D objects is that the entire scene is no longer one big calculation but two. The pyramid is one calculation and the green circle is the second calculation. Because of this, the green circle is rendered on top, not because it's closest to the camera but because its layer order. If I drag the parent to the bottom, the green circle appears below the pyramid. I'll undo that. So does this mean that once a group is rasterized that it's now a 2D object or flattened somehow? Not at all. I'll orbit around it a bit and you can see that everything behaves as you'd expect with a 3D camera move. Rasterization limits how the rasterized group interacts with the other groups in the scene. I'll set the parent group blend mode back to pass through and now the green circle is pierced again by the pyramid. Also remember that rasterization usually happens to a parent group, not the child objects. Click on the green circle object itself and we see that it has a blend mode set to add. If I change it to normal, it's still not rasterized and interacts with the rest of the 3D scene. I'll orbit a bit. So how does this relate to filters? There are certain filters which force rasterization. This time I'll pick the parent group of the pyramid. I already have three filters applied which are currently disabled. I'll enable Gaussian Blur. Now we have a blurry pyramid but it still pierces the green circle so the Gaussian Blur Filter is safe for 3D. Turn that one off and turn on Circle Blur and the pyramid is rasterized. See the box around the group? Now I want to look at the Filters Tab in the Inspector and notice that we do not have an LED next to the filter so don't expect that to appear all the time and don't rely on the LED as your sole warning of rasterization. Trust the box here instead. So Circle Blur is no good for us. I'll turn it off and turn on Light Rays. This is a pretty cool effect and I'll orbit it again, with the light seeming to emit from the entire pyramid. But the lack of interaction with the 3D circle is annoying. I'll turn that filter off. Well, as long as we have Gaussian Blur, which doesn't rasterize, we're not really missing being able to use the Circle Blur Filter very much, are we? So I'll delete it but do we have an alternative for Light Rays? The first thing you should do when this happens is see what the group looks like when you apply the filter to its child objects. So I'll Option drag the Light Rays Filter to every side of the pyramid. We get the interaction between 3D groups back but the Light Rays doesn't look like they're coming from one 3D object, just separate pieces. So I'll get rid of those Light Rays Filters altogether. So I know that another Glow Filter I've used before doesn't rasterize and that's Bloom. Not bad but if I also turn on Gaussian Blur and fiddle with the sliders a bit, then I can approximate the Light Rays Filter pretty well. Filters in 3D can be a bit tricky. You may have to experiment to find the right filter or combination of filters to get the effect that you want. How can you be sure to avoid rasterization? Apple has an online version of the Motion Manual that you can reference here and there's a PDF version that you can download. In that there's a page that lists the filters that rastersize 3D groups. So you may want to try a filter out on a per-object basis at first. In general and I admit this is a big generalization, ask yourself what the filter does. Is it more of an image processing effect like creating a border around an image or turning the image into newsprint? Would you expect to see a particular filter applied to a flat image or a 3D object? If you think it more likely to be used an image processing effect, then the chances are that the filter would not work on a 3D group.