Integration Between Illusion and Imagine
Part 1

So you want to include an animation you've created in Illusion within a 3d rendered scene? While Illusion can handle Alpha-channels allowing you to combine a previously rendered scene and your Illusion animation obviously there are some things this method just can't handle. For example, if you want your Illusion particles to cast shadows or if the camera moves a lot then the alpha-channel method has severe limitations. Hence the following tutorial.

To begin with you should download the following Illusion Emitter;  18k

This is a simple smoke plume type emitter. As you will see, after you've un-zipped & loaded the emitter, I've altered the Stage size to fit the Emitter. In this case to 160 x 400 pixels but you can change this to suit the Emitter your using in the View->Project Settings Menu. Leave it as it is for now.

Once you've loaded the emitter it's time to make an AVI of our smoke so click on the Save Output gadget on the tool-bar at the top, specify a filename, set the animation to render frame 1 - 200 and pick a codec. I use Indeo 5.1 as it gives OK quality and lots of programs support it.

So now you should have an AVI of the smoke which can be applied to an object in Imagine. But obviously you don't want a black border around your smoke when you render it! So now we'll create a Filter Mask AVI to go with the normal colour one we just created.

Go into the Project Settings in Illusion and click on the Background Colour gadget. Set the background colour to white (ie 255,255,255 RGB). Click OK to select and the OK to exit the Project Settings.

Now in the Hierarchy window on the left right-click on the Fast Smoke name and bring up the Emitter Properties window. Click on the Tint Colour gadget and set it to black (ie 0,0,0 RGB). You should also check the Tint Strength setting is set to 100% to give an emitter that looks like this;

As before, click on the Save Output gadget and make an AVI of the emitter but this time call it SmokeFilter.

Once that's finished load up Imagine and create a primitive plane with a width of 160 and a height of 400. Now select the object, bring up the attribute requester  (F7) and click on the Object radio gadget in the top right of the requester (it's the third one down). Select the Maps tab and click on the Add Brush gadget. You'll have to change the File type at the bottom of the requester to AVI then select the 'Smoke.AVI' file you created first. Click apply and you should see the first frame of your smoke AVI appear on your object.

Now click on Add Brush again but select the SmokeFilter AVI. Then click on the Properties gadget followed by the Usage tab. On the left uder the Full RGB heading click on the Filter radio gadget. Click OK and you should have you smoke nicely filtered around the edges but thick & 'smokey' in the middle!

Save the object and load it into a scene in the Stage Editor. Using AVIs in this way is great because you don't have to create States for the object. Just render the scene and the AVI will animate by itself.

Jason Gold