Getting started with Iray

Many of you expressed an interest in doing renders, so I thought I'd do a little tutorial on basics. Like many, I use Daz Studio, which is free but every other prop is behind a paywall. The good news is, the render engine is also free, and you can still tinker with the default figures and free props you can get here and there.

Note that I won't touch scene and lighting setup here. There are better tutorials for these, and I want to address setting that many users seem to overlook.

0- Basic setup

For some reason, the default settings don't allow GPU use for the interface. Go to edit/preferences and set "Display Optimization" to Best. I also set Hardware Anti-Aliasing to Off but it's a matter of preferences.

In the Render Settings tab/Advanced, check if all the devices are checked. You never know.

In Render Settings, turn "Spectral Rendering" on. I won't go into details but it improves renders, at the cost of rendering time.

If you DON'T want Daz to use all your CPU so you can still browse the internet, Just remove the CPU from the rendering devices: it will not contribute much to any decent GPU. Then open the task manager, and in the Details tab, right click the Daz process and click "affinity". You can then choose how many cores Daz will use on your CPU (it will still use it, just not for rendering).

1- Prepare the scene

To make realistic renders, you need surfaces that reflect light. Hit Ctrl+a, then select all the surfaces in the surfaces tab editor. with these selected, double click the Iray Uber Base shader in the Presets tab Shaders:

   

2- Crank up the camera angle

Not really a render setting, but the default camera's perspective is kinda weak. I like to make things more dramatic with a wider angle! You can either select the camera and tweak the focal length in the parameters, or simply right click/hold the zoom icon in the working view. Here's the test scene with a single pointlight and the default camera, and then a stronger perspective:

3- Add area lights with... point lights?

Yes, point lights can be used as area lights, no need to make emissive surfaces! In the pointlight's parameters, select the desired shape in Light/Light geometry. They are self-explanatory, except for the Rectangle and Disc ones which effectively turn it into a 180° spotlight along -X axis (and +X if "Two Sided" is checked). The scene gets softer shadows with a 20cm wide sphere:

4- Tone mapping

The Render Settings/Tone Mapping allow the camera to be set up as a real life camera. the default Film ISO (100) is meant for VERY bright scenes, 400 (for interiors), or 200 (for studio setups) are much more relevant for usual scenes. Here after adjusting the lighting, the difference is subtle but it usually helps to set it up right from the start:

5- After effects

In Render Settings/Filtering, you can add some post-render improvements. Bloom adds a glow around bright surfaces: the lower the "Threshold", the more of the picture will glow, while "Radius" and "Scale" determine the size and opacity of the effect. Bloom is dependent of Film ISO, so if you have to set the Threshold very high, your Film ISO is probably too low. I also lower Pixel Filter Radius to 0.5, to avoid blurring the picture. If you are rendering in a new window, you can click the left border of this window to bring up the Filtering setting, and tweak them without resetting the render:

   

6- Image editing

Just like a real picture, a render needs some editing to look professional. I mention it here because it means making a darker and less contrasted render than needed, so that it won't saturate, and be easier to edit. I personally use the Viveza tool in the Nik collection, which is free. If you can't/don't want to use Photoshop, it's possible to use it with Paint.net with some tweaks. In addition to usual contrast/saturation/brightness adjusting, I always do a level correction, then weak sharpening:




Feel free to suggest your own tweaks! If this was of any help, or if you just enjoy my stories, please consider supporting me on Patreon!