[SItoA] Installing the alShaders in Softimage

Cross-posted from the Arnold Support Corner.

Here’s how to install third-party, SPDL-based shaders, like alShaders, so that you can use them with SItoA.


In these instructions, $AL_SHADERS is the location where you extracted the alShaders download. For example, C:\solidangle\alShaders\alShaders-win-0.4.0b18-ai4.2.0.6.

$SITOA_WORKGROUP is the SItoA workgroup location. For example, C:\Users\StephenBlair\softimage\workgroups\sita-3.3.0-2014.

  1. Copy the alShader DLLs from

  2. Create a spdl folder in your Addons\SItoA\Application folder:

  3. Copy the alShader spdl files from

  4. Restart Softimage. The alShaders should show up in the Render Tree preset manager, and assuming that your version of alShaders is compatible with your SItoA, they’ll work in a render too.

Tip Don’t create an alShader from the Arnold > DLL Shaders menu; it won’t pick up the SPDL and you’ll get a raw PPG (and a raw render tree node too).

Glossy reflections in the Arnold standard shader

In the Arnold standard shader, you use specular reflections when you want glossy reflections. There’s direct specular (the “classical” specular hightlight) and indirect specular (glossy/blurry reflections), and both are part of the same BRDF behaviour. In this screenshot, direct specular (Direct Scale) is turned off, so you see only the indirect specular reflections. The Roughness makes those reflections glossy.

So what’s up with the separate Reflection/Refraction tab? Well, that tab gives you an alternate way to do sharp, mirror reflections (with no blurring or glossiness). However, with Specular, you can get pretty much the same thing by setting the Roughness to 0:

Finally, since I mentioned the direct specular, here’s the shaderball with just the direct spec: