precalculated irradiance map-rendertimes increases to 4times

[JANGLED_NERVES]

Hy there,

I am new to using vRay for Animations, and I figured out an issue which I don´t understand:

If I precalculate the irradiance map (every 5th frame) and use it to render the final Image, the rendering time increases from 5min (single Frame) to 30min.
How can this be? Shouldn´t it be slower, if I precalculate something in the first place?

any clearance for this misunderstanding? D.

[Da_elf]

can you give us a little more info on your method? what types of lighting your using, what kind of GI calculations (Imap, LC ,QMC, Photons etc)

[JANGLED_NERVES]

__Type of Light:
-HDRI in the Environment of vRay (overwrite MAX´s env)
-one vray Light at the ceiling

__GI calculation:
-first irradiance Map
-second QMC

Irradiance map is precalculated to file (auto save, incremental add to current map) and then brought up via the "from file" menu.
I used almost the same setup for Exterior and Interior. If you need more details, ask, I tell you (almost) everything...

D.

[dimo]

Do you have "store with irradiance map" checked in the vraylight?

[JANGLED_NERVES]

No, I don´t.
Does this help and how is the effect on rendertime then? My scene takes too long to try. I thought if I check this, it´s at the end the same amount of renderTime...

I appreciate your help, but I just don´t understand the "what´s going on" during the irradiance map calculation...

D.

[Da_elf]

are you using the bitmap pager?

[JANGLED_NERVES]

If you mean:

Customize -> Preferences -> Rendering (Tab) -> Bitmap Pager

then it´s turned on. Settings:

x on
pageSize 128kB
BitmapSize thrs 20963kB
MemoryPool 50000kB

Wrong?

[Da_elf]

i honestly cant say why. have you done a simple test of calculating a single frame then saving that and reusing it to see if its the same? might be a messup in the scene and you might need to merge into a fresh file.

[JANGLED_NERVES]

Ok,

you are right. I figured it out with a test scene, and it is, like I think it should:

With medium animation - single frame: 58s
with medium animation - irrMap frome file 9s

A funny thing is: if I check the "store with irradiance map" in the light settings, and use the irrMap for rendering, the image looks different!?!

I don´t know why it went wrong in my "big scene". Thanks anyway for helping me.
One little question still exists, which is: Is there a documentation about the function of Irradiance Maps (another than at the vRay help Section)? Do I always have to reCalculate it, if I move some things in the scene? Can I jump into frames in the middle of an animation, preCalculate the irrMap and reUse the whole map, for the changed frames?

lots of questions, help would be great...keep on rendering...D.

[shelsby]

sorry for my ignorance, but what does the bitmap pager do??

thanks

steve

[Candelero]

sorry for my ignorance, but what does the bitmap pager do??

thanks

steve

You can control the RAM usage for the bitmaps in the scene with it.
Otherwise all the maps are loaded in the RAM before the rendering process is started, and stay there (in the RAM) till the end.

It is always recommended to use that with heavy scenes.

Best regards,
nikki Candelero

[olitech]

Don't mean to hijack here, but one thing i wanted to mention regarding irradiance maps....
If you use the wrong irradiance map for the scene, you will notice a huuuuuuuuuuuuuuuuuuge time difference....Make sure you are using the right irradiance map.

I just had a scene go from 13 mins/frame to 6 hours! (no joke)...
Turns out it was an irr. map from a different camera...beware!