extra black prepass Vray irradiance

[BrianKitts]

Recently my settings for my irradiances passes have started to get a little odd.

 

Under Irradiance map settings my min/max parameters are not matching the number of prepasses calculated at render time. For instance settings of -3/-1 has always yielded 3 precalculation passes (as it should). However now for some reason its yielding 6 passes, with the last three being extremely dark.

 

The render still comes out right, but I really want to know what I've set that is causing the extra passes so I can know if its accomplishing anything worthwhile.

 

I've attached an image showing it crossing from the third pass (normal) into the fourth (really dark pass).... anyone gotten this before?

 

Any ideas? -thx bk

[JamesTaylor]

i have had thiis problem in the past!

 

at present i'm not 100% as to the cause but, i think certain material settings can cause extra prepasses. maybe things like a falloff map - it has to calculate the angles of relavent geometry etc.

[lambros]

I think it has to do with material settings, if you use some glossy reflections, this will cause the extra prepasses which are black. No harm done though.

[wcraig]

I concur. Your irradiance map presets aren’t literally how many prepasses you have. From my experience and I could be wrong the prepasses are material related. For example if you have a scene with one plain white material you are going to have the minimum prepasses, where if you have a scene with materials that are transparent, with falloff reflections, and some other translucent ones, you’ll have many more prepasses.

[Tim Nelson]

That is caused when you have interpolated glossies on any of your materials. Keep that unchecked and the IRmap prepasses will return to normal.

[BrianKitts]

yup I bet you guys are probably nailing it, I've started using more and more falloff maps and interpolated materials lately. It would take a bit of work to go through and turn em all off to make sure (so I won't cause its not killing the render time at all) but now I know what's the cause.

 

THX for the knowledge!

[Thablanch]

That is interpolated material related

 

An extra pass does not mean longer renderings, but the opposite

 

The black pass indicates where there is nothing to interpolate, it is going really fast, it will slow down only where it will meet an interpolated material in your scene. There,it is not black, you can see the reflection pass

 

When you are doing brushed metal, leather of satin wood, it is wayyyyy faster to use interpolation. Really nice feature

[goolup]

I have currently been getting the same issue...

 

Now its fine when i'm rendering stills but when rendering animations, the burning out of an Irrandiance Maps doesn't do the 5th pass. Only when I send to render the final image with a pre calculated Light cache and irradiance map the 5th pass is then calculated for each frame. giving me a final output that flickers! Is there anyway to either burn-out this 5th pass or overide glossies on all materials so it isn't calculated, I have hundereds of materials in scene and don't have the time to go through them all.

 

Many thanks

 

Dan

[Thablanch]

No interpolation of materials should be used in animation. This is a cheat, usefull for still images only.

 

(now, since LightCache exists, your materials do not really need to be interpolated, even for stills. LC can turn it on/off with one click only, and it is wayyyyyy faster)

 

You can always refer to this if ever needed:

http://www.spot3d.com/vray/help/150R1/tutorials_imap2.htm

[mzex]

is there any automated way to see which materials are interpolated? and how to turn that off?

I have few evermotion objects in my scene and I get that extra pass, which I would like to avoid.

thank you.