Charging capacitor with a diode in parallel
Initially you can ignore the diode, but once the voltage across the resistor and the capacitor reaches the forward voltage drop of the diode, Vf, it will be effectively clamped and all the current will be shared by the diode and the resistor. No further charging of the capacitor will occur. So run the simulation without the diode and draw a line where the voltage reaches Vf, typically 0.7V for an ordinary silicon diode. There will be the slight inaccuracy due to the I/V characteristic of the diode not being a perfect right angle knee.