Volumetrics Quality / Parameter Change

[rzick]

Sirs,

I just recently noticed a difference in the way that the most recent version of LW appears to handle the volumetric rendering process, and I can't seem to figure out how to get the same results I got before when flying through a cloud. Here is the problem:

Now when I fly through a cloud, at least using 7.5c, I get a certain amount of graininess or artifacting during certain portions of the animation. It appears that the "near clip distance" option has a definite affect on this. However, in the past, I was able to move through the same default cloud preset without getting any of the graininess that you see in 2nd photo. Even pushing the quality setting all the way up to "very good" and setting the near clip distance to ".01 mm", it doesn't seem to go away.

Has there been a change to how hypervoxels work with the volume settings? For the life of me, I just can't get that smooth cloud fly through that I used to be able to get with even lower quality settings. I want to get rid of the grainy, artifacting type look. Any ideas what I may be doing wrong?

I have attached a sample of the bad rendering.

Thanks

Rob Z.
WTBTS

[da_duke]

hm, this can be based on several things. first, i hope you're not using the experimental features of lightwave (toggled with Ctrl+Alt+Shift+F1) it's not generally a bad idea but should be switched off if discovering problems.
next, you have an option at the effects - volumetrics panel (accessed by pressing ctrl+f6) called volumetric antialiasing. so maybe this option is now on (or off) and this is maybe the reason for your problems.
if 'near clip distance' affects the result of the rendering (which is indeed a little bit wierd) it might be possible that you are using hypervoxel sprites? i'm not sure if there is really any relationship but could be possible.
greetings
da_duke

[Hervé]

Can I jump in.... there is aalso a command to make HV account for radiosity or not.... this is ON by default, and I would love to know the stuff you have to do to turn that option OFF, the manual is not very clear on the subject...!

Cheers, Hervé

[Exper]

Originally posted by Hervé
there is aalso a command to make HV account for radiosity or not.... this is ON by default, and I would love to know the stuff you have to do to turn that option OFFHervé...
Lights main tab (on top)
then "Radiosity" button
then if radiosity is activate you can set "Volumetric Radiosity On/Off" parameter. ;)


Bye.

[Hervé]

Really an expert... just kidding... thanks a lot... didn t noticed it as I mainly use the panel when setting up...

Thanks again...!
Hervé

[Exper]

rzick...
I think the problem is "HyperTexture" evaluation: when you're near/inside HVs; it seems like HyperTexture values aren't enough accurate to evaluate small spreads... so... they start to clip values without smoothness.
Note: I'm using LW7.5 (plain, no b nor c).

I don't know if I'm explaining it in a clear way... but let me know what you think about. ;)

Bye.