[Nathan Greene]

Sorry, I can’t help you with animated textures. I have no experience there. My guess is that you’re not going to be able to bring those into After Effects easily. Go with Todd’s suggestion and render out footage items from Blender and use those directly in After Effects.

[Nathan Greene]

In what format are you exporting the model out of Blender? I don’t know too much about Blender, but I’m pretty sure you can export to a variety of formats. Photoshop will import .3ds and .obj, and maybe some others, too. For the work I’m doing, I’m importing .obj files into Photoshop then saving out as a .psd. If you’re working with .obj files, you can see the first part of my post above about editing the .mtl. If you’re working with something else, then I don’t know. You could always reapply the textures in Photoshop (that’s what I did before I figured out I could edit the .mtl), but that’s frustrating when you’ve already done the work once.

[Nathan Greene]

I was just working on this a couple of days ago, but like Todd said, it’s a bit finicky. I’ll tell you how I got it working and some of the problems I’m still having. I’m working in CS5.5 trial, so your mileage may vary.

Before I do that, let me take a stab at answering your texture question. If you’re using a .obj file, make sure the paths for the textures in the .mtl are set correctly (you can edit the .mtl with any basic text editor like Notepad). If you rendered the .obj and .mtl files to one place on your computer and then copied them to someplace else, that’s probably the problem. I’ve also run into that problem when downloading free models online, and changing the paths fixed it.

Now on to compositing multiple 3D objects in AE! The Live Photoshop Layers that contain the 3D objects are linked to layer control objects using expressions in the Live Photoshop Layer’s Live Photoshop Effect (I think that’s what it’s called–I’m doing this on my laptop and don’t have AE in front of me). These expressions use layer names when referencing the layer control objects. Unfortunately, the layer control objects are always named “Layer Control Object”. So, if you have two layer control objects for two different Live Photoshop Layers in the same composition and the two layer control objects have the same name (which they do by default), then both Live Photoshop Layers will be linked to whichever control layer is higher up in the layer list. With me so far?

You can fix this issue by renaming the layer control objects, then remapping the expressions in the Live Photoshop Layers to point to the correct layer control object. Renaming the layer control object by itself won’t do it (although that would be nice).

By way of example, let’s say I have an apple and a table. I copy the Live Photoshop Layers along with their layer control objects into the same composition and rename the layer control object for the apple to “Apple Control”. Then, I open up the Live Photoshop effect on the apple Photoshop Layer and look at its transformation parameters. In CS5.5 they show up red, and I can’t edit them directly because they are expressions. I hit the little triangle next to a parameter to open up the expression. Then I change the text that says ‘Layer Control Object’ to ‘Apple Control’. I do this for all of the parameters that have an expression that references ‘Layer Control Object’. Voila! Both objects should now show up and be controllable from their respective layer control object.

If you followed all that and it worked for you, great!

Now for the bad news: because of the way 3D layers interact in AE, it’s hard to really “attach” them to each other. One layer will always render in front of the other, not like a 3D scene in Blender. So, while you can set up the scene to look good from a stationary camera perspective, you’ll notice some problems if your camera is moving. Objects can appear to “slide” across each other. To return to my apple and table example, let’s say I position my apple on the table and place my camera in a high angle looking down. Then I animate my camera to move down to a low angle still looking at the apple and table. The apple will appear to slide across the table and be in a different spot. For your particular project, this may or may not be a problem.

Now, I remember seeing this same problem explained in this video tutorial by Steve Lidrbauch here on Creative Cow about creating fire with CC Particle World. When you place the particle effect on a floor in a 3D world, it also exhibits that same sliding behavior when the camera moves. Steve shows in the video how to fix that using an expression. I haven’t tried it yet with my 3D objects, but that’s my next step.

All in all, you might just be better off following Todd’s advice above and render out 2D images for compositing. Plus, you can probably get a better-looking render out of Blender. Eventually, I might end up doing that myself, but for now I want to see how far I can push AE’s 3D scene building.