//Box dimensions are integer values from 1 to 10
//Box dimensions are updated with a slider, the properties of which are set in the editor
private void UpdateBoxDimensions()
{
//get the old V/T ratio so that if pressure is constant the temperature can be updated
float box_dim = box.transform.localScale.x;
float VT = box_dim * box_dim * box_dim / T;
float new_scale = box_slider.value;
//box dimensions are limited, so constant pressure can only apply whilst the box is free to change volume
if (new_scale == box_slider.minValue || new_scale == box_slider.maxValue)
{
isPressureConstant.isOn = false;
}
//check if this should be a constant pressure calculation - if so then also update the temperature
if (isPressureConstant.isOn)
{
T = Mathf.Round((new_scale * new_scale * new_scale) / VT); //ideal gas law for constant pressure
temp_slider.SetWithCallback(T, false); //set the slider without calling the event handler
//now set the new temperature and reset the particle system
//update the most probable speed
vp = Mathf.Sqrt(2 * k * T / m);
//update the gas particles. since temp has changed need to recalculate the speeds and then set them
CalculateAndSetSpeeds(m, T, N, divs, vp);
}
box.transform.localScale = new Vector3(new_scale, new_scale, new_scale);
IdealGasParticlesSystem.Clear();
var s = IdealGasParticlesSystem.shape; //the shape module which should be a box
s.scale = new Vector3(90f * new_scale, 90f * new_scale, 90f * new_scale); //make the scale 90% of the box size but also multiply by 100
IdealGasParticlesSystem.Emit(N);
//reset the particles to the correct speeds - since this is only affecting volume, speeds do not change, so no
//need to recalculate (if constant pressure then calculation is done in above if statement).
SetParticleSpeeds(N, vp);
//Update graphs
PlotPVTGraphPoint();
}
//Updates the temperature and then resets the particle speeds
//if input field was used to change the temperature then run with input = 0; if slider, then input = 1
//If pressure is set to be constant then when updating temperature, also need to update the volume accordingly.
private void UpdateTemperature(int input)
{
//get the current V/T ratio, before the new temp is set
float box_dim = box.transform.localScale.x;
float VT = box_dim * box_dim * box_dim / T;
float temp;
if (input == 0)
{
if (float.TryParse(temp_input.text, out temp))
{
if (temp >= min_temp && temp <= max_temp)
{
T = temp;
temp_slider.value = T;
}
else
{
temp_input.text = T.ToString("F0");
}
}
}
//if input is not 0 then the slider was used to change temperature
//the slider properties have been set in the Unity editor
else
{
T = temp_slider.value;
temp_input.text = T.ToString("F0");
}
//if pressure is constant then this temperature change should cause a volume change in proportion
//The volume needs to change without calling the box_slider on value changed event since that would start an infinite loop
if (isPressureConstant.isOn)
{
float new_V = VT * T; //ideal gas law for constant pressure
float new_scale = Mathf.Pow(new_V, (1 / 3f));
//set the box slider to the new value but not not call the update volume function
//only do this if the scale the box will be set to is within the min/max box scales
//if it isn't then switch off pressure being constant
if (new_scale >= box_slider.minValue && new_scale <= box_slider.maxValue)
{
box_slider.SetWithCallback(Mathf.Pow(new_V, (1 / 3f)), false); //assign the new box dimension - this will call the update volume method
//now set the new volume and update particles
box.transform.localScale = new Vector3(new_scale, new_scale, new_scale);
IdealGasParticlesSystem.Clear();
var s = IdealGasParticlesSystem.shape; //the shape module which should be a box
s.scale = new Vector3(90f * new_scale, 90f * new_scale, 90f * new_scale); //make the scale 90% of the box size but also multiply by 100
IdealGasParticlesSystem.Emit(N);
//reset the particles to the correct speeds
SetParticleSpeeds(N, vp);
//Update graphs
//PlotPVTGraphPoint();
}
else
{
isPressureConstant.isOn = false;
}
}
//update the most probable speed
vp = Mathf.Sqrt(2 * k * T / m);
//update the gas particles
CalculateAndSetSpeeds(m, T, N, divs, vp);
//Update graphs
PlotPVTGraphPoint();
}