aiMixShader question?

[tsewingsum]

hi all,i testing the aiMiShader render test.i find the aiMixShader incerase more render time. Case 1.

• object : 1000 cube
• shader : aiStandardSurface1
• light : skyDomeLight
• AA Sample : 10
• render time : 11:00min

Case 2.

• object : 1000 cube
• shader : aiMixShader
  • shader1 : aiStandardSurface1
  • shader2 : aiStandardSurface1
  • Mix Weight : 0.5
  • Mix Mode : blend
• light : skyDomeLight
• AA Sample : 10
• render time : 20:00min

my aiStandardSurface1 not connection other node Case 1 and Case 2 is same aiStandardSurface setting

So my question is, why aiMIxShader incerase more render time? And How to optimiza aiMixShader? Cheers, Sum

[timh5D75Z]

My understanding is it would be running each shader separately and combining the results, so it makes sense it would double render time. What you can do instead is use the mix shader on inputs to a single standard surface, such as mixing the diffuse texture from several input sources before plugging them in.

[maxtarpini]

@Tim Harding at that point probably an aiLayerRgba is a better choice.