Active Shade - Gamma problem

[phizikl]

i know there is a thread in here with a similar issue, but I did not understand the solution.

I have a scene, i always look at it with sRGB lookup table in VFB and have vray gamma to 1.0 (everything linear, only lookat 2.2) (and i also set max gamma to 2.2 to lookup correctly for max FB(&active shade window))

but in active shade i get a much darker version than VFB (sRGB turned on, and even OFF is still brighter than active shade) i tried increasingi RT gi settings, but makes no difference,

the active shade even with vray set to 2.2 is still darker, so, even when i have vray gamma to 2.2, AND max gamma to 2.2 (so getting DOUBLE GAMMA) the image still does not have the correct brightness

ok- i just saved out active shade image, with the maxoutput settings of 2.2 it saves me a BRIGHTER image than it displays in max- that doesnt make sense


to sum it all up:
-the saved out active shade images are brighter than displayed in viewport (vray1.jpg)
-saving out active shade with vray set to 2.2 gives me close to the sRGB VFB normal render, but i dont see this brightness in active shade, only after saving
-i can not get the same result in my active shade as the picture vray22.jpg- whatever i do, active shade FB is darker than the normal render

your help is appreciated

[phizikl]

and just to make sure
i rendered with vray gamma to 2.2
now we can see, in VFB i have sRGB turned off(else too bright) and now active shade is brigher than above pic, but, its always one gamma "behind"... its still too dark!

but now, when i save it out (i have gamma output to 2.2 for my preview renders) its a bit better, not so dark anymore... so how does that all work?

if i have my max gamma to 2.2 (for the lookup) and vray gamma to 1.0, should i not get the same result in active shade, as i would when i render with VFB (and sRGB on) OR when i render with MAX FB (max gamma at 2.2)

[vlado]

Which V-Ray and V-Ray RT versions are you using? The gamma issues were only solved for V-Ray 1.5 SP4a + V-Ray RT 1.5 SP1a.

Best regards,
Vlado

[vlado]

Looking at the images, I'm not sure it is gamma issues that you are seeing. Do you have any lights in the scene or just GI?

Best regards,
Vlado

[phizikl]

please tell me, where can i get RT sp2 ?

http://rapidshare.com/files/37635371...06_RT-Test.zip


i have two vray lights,
i cannot get same look with RT, sorry for the trouble

i am using sp5 (beta-compile for particle vertex coloring) and rt sp1a

[vlado]

I meant V-Ray RT 1.5 SP1a, sorry for the confusion; thanks for the scene - will look at it.

Best regards,
Vlado

[vlado]

The difference is because you are using a "Movie camera" type for VRayPhysicalCamera; it is a known issue and we'll fix it.

Best regards,
Vlado

[vlado]

Hm, there seems to be something else too...

Best regards,
Vlado

[vlado]

Ok, the other reason is the "Store with irradiance map" option for the lights. Since the RT does not use irradiance map, they end up being black (which would also happen in the regular V-Ray if you switch to "Brute force" GI for the primary bounces).

Best regards,
Vlado

[phizikl]

of course, just brute force
thanks alot, learned my lesson!

i just tried vray RT with 2 computers!

wow, nice! much faster (obviously =)


guess i have to work with brute force and no irradiance, if i want to work with RT on this scene?
but i think its worth it, i WANT to work with RT because i dont constantly have to rerender to see what im doing, or do you have a workflow to work with RT and use lightcache irradiance production render settings?

will an automatic compound mesher be included in next version for particles? just good with different events and different materials for automatic render, tedious to set it up JUST for rt, but otherwise im back in love! cant wait for gpu

[vlado]

You just need to turn off the "Store with irradiance map" option for the lights. We should be able to do this automatically for the RT for the next update.

For particles, there will be an option turn them on, yes.

Best regards,
Vlado

[phizikl]

ah right, works great now, thank you

[phizikl]

For particles, there will be an option turn them on, yes.

Best regards,
Vlado

would be cool, because i just ran into many bugs with the mesher, activeshade doesnt update correctly, changing shape in pview crashes max, and some other problems