Car Commercial – 5 – Multi Prim Noise

A quick little update on something I realized I didn’t do completely correctly that allows a bit more control. In the current set up, the noise functions used to offset each primitive is offset by the current prim number. This helps simulate branching and clumping tendencies. But what if its too much or too little or we want it only at the ends?

We take our curveu parameter to get where we are on our primitive and map that to our ramp. This ramp will determine how much noise differentiation to introduce at that point of the primitive. We have an overall multiplier for global control also. We get a random value from our prim number and multiply it with our multiplied ramp output. This way we get the same amount of relative offset on each primitive. This number is then turned into a vector and added to the time offset. This is all then piped into the offset of the noise. This way not all the prims have the exact same offset, but still offset at the exact same rate.

Here’s the UI. You can see just exactly where we see the offset amounts. This system is awesome because I don’t have to worry about the offset changing between prims even if they aren’t in the same location, because it works on a position basis, therefore since these points start at the same position, they get the same noise. Nice to not have to think about.

A final regular setup. Note that the lightning isn’t nearly as drastically offset at the start and end. This is the noise offset from the initial set of sliders and controls.

Sometimes the noise can be not exactly what it seems to reflect in the graph and this is because its simply shifting the offset, not multiplying the actual amplitude. This set up can definitely be directly plugged into the amplitude, but I don’t think it is currently completely necessary. By increasing the offset of the prim, as we drastically increase the offset we will see more and more noise being crammed into any certain range we set. You can also sometimes see a slight mirror or peak when the ramp hits its max value and drops again, basically it looks as though the noise is emitted from the middle of that curve.

This is to be taken with a grain of salt, the values shouldn’t be this high and will constantly be moving anyway, but its good to know its limitations.

This is one of the videos I have been using for reference. I thought I was dialing noise and Offsets up too high but in reality lightning and electrical arcs are all different crazy shapes. Its worth to realize however that these shapes might still look too cartoonish or fake, despite being real, so a balance has to be struck.