Strata has this funny little quirk, an object must start at the 0 point of the timeline. So the question always comes up, what if I have an object I don't want to show up until frame 600 of an animation? Well with a quick stencil map you can control the visibility of any object an make it appear or disappear whenever you want. Here is the simple solution for this little problem.

Okay first off lets start in Photoshop with a two layer texture. Make one layer a color for the color channel and the other layer will be all white. The white will be the stencil layer that will "cloak" the object it is mapped to. Save the texture as a photoshop file that you will load later.

Next, I put down a simple sphere for the example but you can make any shape you want for this.

After you have a shape down you like it's time to make a new texture. in the resource window with the texture tab active click on the "new" button to make a new image texture. Next, load your photoshop texture using the "Load" button at the far bottom left of the texture window. Use the pull down menus next to the channels to load the color layer of the photoshop file into the diffuse color channel and the stencil layer into the stencil channel. Here are the key points to remember on this, make sure you have the stencil channel set to stencil and the "Edit at" button checked to current time. Now you can apply this image map to your object.

Once the image map is applied to the object turn down the arrows of that object in the project window until you see the surface shader info. To change the visibility of the object with the image map on it, slide the time marker down the time line. Next, click on the edit button next to the texture name in the project window.

When you checked the edit button the image texture window will open. Now, change the percentage to 0% and the object with the image texture will disappear at that point in the timeline. Notice above a new key frame is added.

That's it! You can control when an object appears or disappears from your scene with the use of a stencil channel. There are other things that can be done with this technique. Imagine if you had an object with multiple image maps that morphed into each other over time. Anyway I hope this will open up some possibilities for you. Check out the example .mov below to see it in action.

download example .mov here