Getting different renders than others

[ChristopherC]

Hey gang!

Some display-related things seemed a bit off on my old laptop (MacBook Pro with no dedicated GPU) so I upgraded to a new laptop (Dell XPS 9560, Ubuntu 17.10), installed Houdini 16.5 Indie with vanilla preferences, and decided to check if my results would conform to other people.

For that, I picked Steven Knipping's free introductory tutorial to volumes and rendering, and followed the instructions up to the end of the 2nd chapter (at the 15:15 mark). I tried to recreate the exact same scene (including his parameter values) but noticed two differences anyways:

- the volume shading in my viewport is much darker—but it could be understandable with different GPUs
- the Mantra rendering is also much darker, and that I really do not understand.

To get a closer result to Steven's, I need to multiply the intensity of both key and fill lights by 10, as seen below.

I thought that maybe something changed in Houdini 16 or 16.5 (he is using 15.5 in his tutorial), so I also installed 15.5 Indie (again with vanilla preferences) but ended up seeing the same results.

So the questions are:

- what's going on?
- what kind of result do you get when displaying/rendering the scene attached?

001.hiplc

[ChristopherC]

Okay, I think I found what's going on.

Steven said in a Vimeo's comment that he's using Houdini 15.5 but in fact his `_HIP_SAVEVERSION` variable is pointing to 14.0 and, starting with Houdini 15.0, lights now default to physically correct attenuation. Disabling the attenuation produces the same renders as in his tutorial.

Good to know that my Houdini doesn't misbehave, phew!