Ridiculous rendering speed

[mzmeskal]

Hi guys,
Here I am with a nother problem... I have this scene with unfinished sofa...Everything was fine until I added some skylight portals into the windows.... the unfinished render below was renering for 9 hours!!! and still not even half way finished...I dont really know what to do...I have no fancy setting on, except for gloossy refl on the floor. The IR map is finished within 2 hours but then the rendering takes FOREVER!!! Please help...I beg you cos inthese conditions I cannot really finish project I ve been working on for quite a long time....



Thank you!!!
Best regards
Martin

[natty]

hi
can you post your scene.
these times seems to be way way to high

[mzmeskal]

The scene is way too big...over 40 MB....

I just rendered another image with those two skylight portals turned off and the time droped to 1 hour....

I just cannot believe that this can be caused by two skylight portals....I thought that the portals affect the IR map calculation time NOT the rendering itself....

... I have 10 subdivs for the portals and no smoooth surface shadows....so whats the problem than????

Thanks for quick reply though!!!!

Do you have at least any idea what might cause this???

I must admit that I have only 1.4 Gh Athlon with 512MB of RAM, but I never had this sort of problem...

...the rapid slowdown occurs only while rendering after the IR map has been calculated already.....

[GoncaloP]

How much glossi reflectioms are you usung? 3-5 should be enough.... for the other Vray light, you can change it to be stored with irradiance map, if you use more than one Vray light they usualy became slow since they uses direct computation to trace light.

Gonçalo

[percydaman]

that scene is 40 megs? how is that possible?

[Psy]

are the portals set to add to ir map?

[mzmeskal]

To Psy:
No the portal are not set to store with IR map...does that change anything? I mean does that affect the speed?

T Goncalo:
Wha do you mean how much glossy refl? you mean subdivs or materials with glossy refl? with the lights that means that these light are counted after the IR map is done...how much time do you think it could save me????

To Pecydaman:
Firstly I though its your mat setting that causes the slowdown, but afterward I found its the light setup....the scene is sio big cos it stores all the mats and probably all the textures, that are used on the other side of the scene.....and also I think the size is affected by the high polycount that is caused by transformed powersolid surfaces...

Thank you guys for all the replies Ill try to change the settings and post the result...!!!!

[Dman3d]

If you are generating a solution and then rendering from it you should
have store with irmap turned on for the VRay lights, if not it will just
re-calc them when you render essentially not helping w/ the time.

The materials with the glossy reflections: the subdivs in the reflection area
of the material can be turned down to about 3-5 if not already,
I believe this is what GoncaloP is referring to.

I find that in some cases fixed rate at 3-4 w/ random checked can be
faster compared to adaptive sub (at least in terms of animations) might
be ok in this case, try a test.

To get that files size down you might want to remodel the couch in MAX
using simple chamfer boxes, IMO.

[mzmeskal]

Allright....here is the result....I checked store with IR map and the times droped to 2 hous for the whole render (IR map + render) and here is the result...


Thank you very much for help!!! I really appreciate it.

To Dman3d:
store with IRMAP really helped to dave me the render time!!! I really did not get wht you meant by saying that it wont help on reducing render time....no offence though...I really appreciate your comment it was much help too.
The couch is modelled with chamfered boxes with many segments, cos I have some noise modifies applied on it to give it more softer and upholstered like look.

Now Ill just add some pillows and legs....
Thank you again guys...I am glad you are always there to help!
Best regards
Martin

[Dman3d]

Glad it worked out for you. Just to clarify, if it was not checked time would be long, with it checked it gets stored w/the irmap rather than re-calculating
them at render time.

Looks good!

[GoncaloP]

I ve just see the AA noise threshold you are using do you really need so high value for it? I never had to use less than 0.05, and that is already slow.... I m sure you can use a lower value and this will save you a lot of the render time

Gonçalo

[TRGraphics]

Even two hours seems very long for such a simple scene.

Have you tried doing away with the noise applied to the cushions and using a displacement map instead? It will cut the time drastically and look better as well.

This simple scene should render in a matter of minutes not hours, of course your machine has a lot to do with render time, but still, it can be done much faster with the tools provided in vray.

Also, as GoncaloP said, that noise threshold is way to low for this scene. try .05, as suggested, if you feel you must reduce the setting. But if you use a displacement map instead of noise on the geometry, even .05 will probably not be neccessary. Have fun!

Tony

[TRGraphics]

Dman3d - I was not aware that you have to save the ir map to file in order to get the benefit of checking save to ir map under lights. I will have to test this and see if I've ben missing an important feature! Thanks

Tony

[GoncaloP]

You dont need to save to a file the irradiance map, but you need to check the "store with irradiance map" option in Vray lights to be computed by the irradiance map, instead of brute force with the AA process. I think that is what Dman3D was talking about.

[TRGraphics]

Thanks G, I was a little confused by what he said, I guess. I've always checked that in lights.

By the way, I've been using photons lately due to your excellent posts on the subject. Thanks for your efforts, it is saving me a great deal of time on my renders!

Tony