Render parameters are values or colors used by shaders to provide different results. You can adjust them in real time.
To change the parameters, select the mesh you want to change. Depending on the shader the model can have none, one or multiple render parameters. Their purpose is explained briefly below each one.
To edit write a new value in the text field or drag the slider.
For colors, click the color field and then select a new color value.
The object in the render window automatically tracks the value value while you change it.