There are various ways of making fog in Octane, and all of these are volumetric fogs. Here we will explain the ways of making volumetric fog in this section. Fog is a less complex nature phenomenon than fire. Nevertheless, making a realistic fog is always a hard job and since there is no emission like a fire, the most important things here is the Light and Volume medium setups. If you want to follow the tutorials we discuss in this section, you can download the scenes from the link below.
Download "Fog_01" scene from here
Download "Fog_02" scene from here
creatIng local fOG usIng volume fog object
In Octane you can create both local and global fog. Now open the "Fog_01" scene. This scene is the classic indoor scene and obtained from the content browser of Cinema 4D. If you're ready, let's start.
01- Go to the Objects menu from the Live Viewer and create an "Octane Fog Volume". Then change the coordinates and parameters of this volume object as you see in the picture below.
02- Now from the Live Viewer go to the Objects menu and create an "Octane Daylight" from the Lights sub-menu. Then change this Daylight's coordinates and parameters as you see in the picture below. This light will interact with the Fog object on the scene.
03- Now we can do Volume medium settings for the Fog. To do this, select "Volume Fog" from the Object Manager and go to the Medium Tab. Change the settings as you see in the picture below.
05- Now run Live Viewer. If you have done everything right, you will get the result you see in the picture below. As you can see, the volume fog object you have placed in a certain part of the scene has created the desired effect. You can add a completely different atmosphere to the scene by playing with the position of the light and the Density and Step Length settings of the Volume object.
Or you can add some variation to Fog using noise. To do this, go to the Generator Tab and assign Cinema 4D noise to the texture slot. You can select the noise type you want from the Noise settings. In the picture below, Naki noise is used, and as you can see, the scene is appeared with another atmosphere. If you animate this noise, you can create a moving foggy smoke effect. Options are endless.
creatIng global fOG usIng envIronment medIUM
In this tutorial we will show how to make an environment fog. The difference from Local Fog is that it covers the whole scene. Now install the "Hot4D" plugin for Cinema 4D before opening the "fog_02" scene. This plugin creates a realistic ocean (not material, only mesh). It's a pretty nice plugin and free. You can download it from here. / Of course you can also use houdini for the sea/ocean simulation (which is much more advanced).
01- Open the "Fog_02" scene. First create an Object / Lights / Octane Daylight from the Live viewer menu and change both the settings and the coordinates as you see in the picture below. We will make the main fog setup within this light later.
02- Now create the Object/HDR Environment again from the Live viewer menu and change the settings as you see in the picture below. The reason we use this HDR is because it contributes to general illumination and local shadows.
03- Now select Octane Daylight Tag from Object manager. Go to the Medium tab and assign "Scattering Medium" to the medium slot. Make the medium radius 3000 cm.
04- Click Scattering medium. Here you assign "RGB Spectrum" to the Absorption and Scattering channels and change the settings as you see in the picture below.
Info: Volume Step Length has no effect on Environment Medium.
04- Now run Live Viewer. If you have done everything right, you will get the result you see in the picture below. As you can see, we created a global fog using Daylight's medium channel. Because of the high absorption and scatter in the fog phenomenon, we made our adjustments accordingly. For example, in the absorption channel, the higher the "V" value, the more it is forced to absorb the rays quickly. As in reality, the rays will quickly absorb in any dense fog. Also the scatter phase plays a very important role in the scene. The rays scattering towards the source of light ensure that the scene looks like this. That's why we see the front rowboat a little clearer. You can play with the settings and create the atmosphere you want.