Underwater Caustics in Superfly
This tutorial will show you how to create the effect of “caustics” and depth for your underwater renders in Superfly. It was created in Poser 14 but should work in 13 and maybe 12.
Step 1
Firstly, you are going to need an image file of seamless water caustics in black and white. There are several free and commercial caustics generators out there. One such free generator can be found here. Or you can just use the pattern I created for this tutorial which you can download along with the other tutorial files at the bottom of this post.
Step 2
Start a new scene or use an existing scene you want to add caustics to. For the sake of this tutorial, I suggest starting a new scene first. In the Poser 14 Content library, go to Props –> Primitives and load a Square prop. Flip it on its side by setting the xRotate to 90°. Move the prop to the very top of your scene and increase its scale to cover your entire scene plus a little extra area around the scene. In the tutorial scene, I increased its Scale to 20000%.
Step 3
Go to the Material Room and then use the “Edit” or “Advanced” tab depending on your Poser version. Create Physical Surface root node. Now attach an Image Map node to “Color” and “Transparency”. Set the Color of the root node to white and the Transparency Value to 1.0. Load your caustics pattern as the Image Map node’s Image Source. Make sure to set the Custom Gamma value to 1.0 then click OK. In the U_Scale set the value to 0.05 and then do the same with the V_Scale.
Step 4
Now for the light setup. Use Scripts –> Utility –> Delete Lights to delete all of the lights currently in the scene. Create a new Spot light and name it “Caustics Light”. Position the spotlight so that it is pointed downward from the very top of the scene above the square prop. Set the lights Parameters to what you see in the example image. You can set the light’s color to whatever you wish. The most important settings are to set its Intensity to a very high value such as mine at 5000% and make sure that Shadows is checked ON in the Properties tab.
Step 5
Now we will create the water’s volume and depth effects. Add a Box prop from the Props Library in the Primitives folder (same as where you got the Square prop). Increase its scale to fit over your entire scene. For this tutorial, I have set it to Scale 7500%. It needs to be positioned so that it surrounds the camera you are using as well. This will ensure complete immersion.
Step 6
Now go back to the Material Room. Create a Cycles Surface root node. To the root node’s Volume channel, add a Principled Volume shader node. It is under Cycles –> Shader –> PrincipledVolume. Set its properties to the values seen in the example screenshot. Note that the Density value is what increases the thickness of the volumetric effect. Set it to a low value such as 0.04 and you can also experiment with this value as you see fit to get different looks.
Additional Info
Make sure you have Volume Step Rate and Volume Bounces set above 0 in order for the volume and depth effects to work. My render settings for this tutorial scene are pictured here. You can experiment with different render settings to get different results.
Click the button below to download my sample scene and caustics image map in a zip file. If you are using a version of Poser older than 14, don’t worry about the “newer Poser version than expected” warning and just click OK.
