we generally leave near and far planes out of the internal matrix, and use function:
```c++
	ofMatrix4x4 Projector::getClippedProjectionMatrix() const {
		if ( this->isProjectionMatrixInfinite() ) {
			const float n(0.01f); //near
			const float f(10.0f); //far
			ofMatrix4x4 projection = this->getProjectionMatrix();
			projection(2, 2) = - (f + n) / (f - n);
			projection(3, 2) = - f * n / (f - n);
			return projection;
		} else 
			return this->getProjectionMatrix();
	}
```

when we want to get a projection matrix with near/far planes.


ideally we should have `setNearClip(..)`, `setFarClip(...)`