Opacity performance - LOW!

[cecofuli]

Hello guy,

we know, opacity is a very "killer render time" beast!
I wanted to see if there is some boost with the new Coronabitmap
Unfortunately no. But I noticed that, with opacity OFF, I can have a 2.5X boost! WOW!
Ondra, maybe can you improve something? Like in VRay?


Thanks!

[romullus]

Comparing opacity vs no opacity in Corona and filtered opacity vs non filtered opacity in Vray isn't very fair.

[cecofuli]

Yes, but for static rendering, I would like to get the lower rendering time possible. If non filtered can help, why not?
I tried with CoronaBitmap to change filtering blur and interpolation. No differences.

[Ludvik Koutny]

Corona disables filtering for all opacity maps by default, so there is not much more to gain there.

It's not much of a surprise that opacity maps (especially as fine as conifer needles) will reduce performance of raytracer. Compare rendertimes of material with opacity vs material without opacity on same scene in Vray, and you will get same, if not bigger slowdown.

[dfcorona]

Vray has the new Clip Map Opacity to render really fast! Maybe corona can come up with something like that.

[cecofuli]

I know, but, maybe, as VRay does, we can reduce rendering time in such situations. 2.5X is very much!

[Ludvik Koutny]

Doing these two things in opacity map will give you equivalent of Vray's clip mode for pretty much any 3ds Max renderer.

[romullus]

Alternativelly you can make action in photoshop to resave image in indexed color mode, run all your opacity maps through it and forget all headaches with opacity once and for all :]

[romullus]

Did quick non scientific comparison with Mental Ray.

MR
no opacity - 67 s
opacity - 202 s (x3)
opacity + translucency - 1063 s (x16)

Corona
no opacity - 54 s
opacity - 84 s (x1.6)
opacity + translucency - 96 s (x1.8)

So we have nothing to complaint about ;]

[cecofuli]

So, it's a ray-tracer "problem". Nothing to do...  =) good to know, sadly ^___^