In-the-box all you have to do is send a single-sample impulse through the fx chain and render the output.
If there are any non-linear effects in the chain you need to make sure the input level to the fx chain is low enough so that the impulse isn't getting distorted.
Try different input levels (by changing the item volume or putting a volume plugin at the beginning of the chain) and see what works best. I've gone down to -60 dB before to avoid distortion.
If there are only linear fx, this isn't a concern.