There are a number of general methods of approximation that you can use:
- Use compute power where it has the greatest visual impact
Some effects are subtle and might be hardly visible on a mobile device. Make the best use of the available resources by using compute power on effects that have the most visible impact.
- Simplify effects
You can optimize by removing or simplifying elaborate effects. Try changing complex effects to simpler effects that give a similar result.
- Graphics are rarely required to be correct
Graphics are typically not required to be precise. You might be able to use more approximate, simpler computations that reduce correctness to achieve increased performance.
- Simplify equations
Some shaders use complex equations. Try to use simpler, less compute intensive equations to achieve a similar effect.
- Consider different algorithms
You can get large performance increases by changing to more efficient algorithms.