Modifying the model matrix??

Questions & Answers
1

I’ve been playing with some large-scale planet rendering concepts, and I’ve encountered this:

http://www.gamasutra.com/view/feature/2984/a_realtime_procedural_universe_.php

Specifically this:

“I solved both of these problems by scaling down the size and the distance of planetary bodies by modifying the model matrix. Using a defined constant for the desired far clipping plane, which I’ll call FCP for now, I exponentially scale down the distance so that everything past FCP/2 (out to infinity) is scaled down to fall between FCP/2 and FCP.”

I understand that conceptually, but is it possible to scale the model matrix’s distance in Unity? Would I just scale my planet mesh down along the camera’s look axis?

2

In Unity the Transform component covers the functionality of the ModelMatrix (also called world matrix). The model matrix is just a “TSR” matrix (Translation, Scaling, Rotation). It corresponds with the Transforms localPosition, localScale and localRotation. Unity can build a matrix from those 3 seperate vectors.

You can access the matrix with the localToWorldMatrix property of a transform component. However you usually just use the localScale to change the scale.