too slow...

[Bowcat]

Hi!

I'm a Brazil r/s user, and I'm new to Vray.
What I notice is that vray is much slower than brazil, when it is known to be the opposite, wright?
The good thing about brazil is that you can render fast with low quality. For example with photons and a low view rate. that is good for just try the scene.
But with vray I can't get good fast previews.
I folowed vlado's tutorial on photon map.
Is there a way to use photons for second bounces, irradiance for first, and render with very, VERY, low quality so I can preview the scene?

Thanx!
by the way, I'm using a pentium III with 512MB, so....

[flipside]

Untill a few weeks I also used a PIII-800Mhz with vray.

To get fast previews do this (they will look very bad but you can see the lighting good enough):
-set resolution to something low (400 to 600 width)
-irradiance map settings:
min,max=-5,-4
clr=nrm=1.0 (lower is slower - don't go lower than 0.3 for good renders because rendertimes increase exponentially below this number, and visual effect is not worth it! )
dist=0.1
hsph subdivs=10 (the lower the faster of course)
interp samples=10 (this has also big effect on rendertimes! the less interpolating that has to be done, the faster the render!)
-AA settings: adaptive -2,-1

To preview certain regions use max's region select thing and set vray to bucket mode. If you don't, it will still calculate IR map for whole image instead of only selected region.

Hope this helps!

Regards,

flipside

[natty]

hi and welcome to vray ...
first try to stay away from photons at this piont as they are tricky to get to grips with at first, and you really are lacking in memory

you can use the preset's in vray IRR map to get low render times and also play around with the QMC to get real fast render time ... here's a link.

http://www.chaoticdimension.com/foru...pic.php?t=5967

you will find very quickly how much faster vray really is, just keep playing with it.

Regards

[flipside]

Ah yes, forgot the qmc sampler! Looks like a great idea to use high settings in IR map with fast settings for QMC, this gives you better visual results than low IR map settings and high(default) QMC.

[natty]

once you pick Vray up there is no going back ... just stick with it .. you already belong to the best help forum around

[Bowcat]

thank you all!!! I'm going to try qmc.

I got to tell you, I don't know about vray too much, but I know for sure this forum is much better than brazil's

Thanx again!

[cocolas]

but I know for sure this forum is much better than brazil's

you can say that twice

don't get me wrong, the SF forum has some great people on it, helpful and talented, but it's waaaay to dead for me


paul.

[Bowcat]

Natty, I kept thinkin' about something...

You said:

first try to stay away from photons at this piont as they are tricky to get to grips with at first, and you really are lacking in memory

Isn't photon system a way of accelerating things up? at least in brazil is.

I've been playing with qmc and I found that its shadows arn't that good, you know? You must be saying "this guy wants everything!" . The shadows under objects are too wide or something, aren't they? (in your scene the chair looks kind of elevated or not touching the floor). What do you think?

Thanks!

[percydaman]

photonmapping CAN be faster then irrad mapping. but only in specific circumstances and with certain restrictions. Dont use them in an outdoor scene and you have to use vray materials throughout. There are other things to consider and there are a few really good threads in this forum that speak better of them than myself.


percy

[flipside]

Natty, I kept thinkin' about something...

You said:

first try to stay away from photons at this piont as they are tricky to get to grips with at first, and you really are lacking in memory

Isn't photon system a way of accelerating things up? at least in brazil is.

I've been playing with qmc and I found that its shadows arn't that good, you know? You must be saying "this guy wants everything!" . The shadows under objects are too wide or something, aren't they? (in your scene the chair looks kind of elevated or not touching the floor). What do you think?

Thanks!

Natty's scene in the other thread is an example of how to set up things for testrendering only! It gives you few details in shadows, but it shows you the lighting situation with small rendertimes. if you're satisfied, just return the QMC and other settings to good quality values and your details will show up again.

[tom schuelke]

Hi Bowcat

Flipside, Natty and the others are right.

Just stay a while with vray, it´s worth it. And as said, there will be no way back after a while

The forum isn´t the only nice thing with vray.


Well

Photonmapping in Brazil as with vray is an aproach to make renderings faster, only in interior scenes. Highendrenderers, using a backward raytracing algorithm, like both do, have problems, to view small areas of light, searching for the light amount at each sample point. For this, they have to trace lots and lots of rays, to get good statistical results. This problem apears most time in Architectural interior scenes, and the solution for this in Brazil as in Vray usualy was photonmapping.

But like said, it sometimes is a bit tricky to setup, and only works with vray materialals and with Vray lights.

But stay a while with vray. The new Vray version 1.5 will overcome those problems, giving a new aproach, to speed up rendertimes especialy in interiors.

This new method, called lightmap is as fast as photonmapping, but much much esier to setup, and secound it works with each and every way of lightdistribution, Backroundimages, Hdri, selfiluminated objects, standart lights, vraylights, and so on.

this together with imap for first bounce, and qmc will speed up everything.
another thing i dont know about Brazil, is if it can precalculate light like vray and irradiance maps.

This feature is one of the most straightforward things in vray. and After a while using vray you won´t anymore want to miss it.

at last me and Geddart who also works at lichtecht.de, tested some time ago brazil against vray. First vray semed to be 2 to three times faster than brazil for the cost of very fine and small gi details in smal areas. After tweeking vray we could come to the same results as brazil but had to wait the same time.

well i would like to here your thoughts of vray after you did use it a while. It is very interisting to judge vray from a brazil point of view after you have learned enough about vray.

so good luck with it and once again welcome to vray forum


Tom from Hamburg

www.lichtecht.de

[tom schuelke]

Hi Bowcat

ONe thing i vorgot,

The new lightmap method allows to render interiors as well as exteriors, only using lightmap as well for first as for secound bounce. If you stop reflections in your scene using the global settings, you get unbeleavable fast renderings giving a very good aproach of the lightdistribution. as well for exteriors as for interiors.

maybe natty ore flipside, do you know still vlados link to the lightmap examples, he rendered ?

maybe read the long thread in the anouncements, where vlado told some of the new features of lightmapping.

good luck again

Tom

[tom schuelke]

Hi Bowcat

i found the link

http://www.vrayrender.com/stuff/lightmap/

until 1.5 is released, use low imap settings and qmc

Tom

[Bowcat]

Hi Tom!

That Lightmapping sounds great. It remembers me Max's "Light tracer", only faster.

By the way... Coria is playing tomorrow in hamburg's tennis tournament, the finals (he and I are both from Argentina ) Are you goin' to be at the stadium? Cheer for Coria!

Flipside:

just return the QMC and other settings to good quality values and your details will show up again.

Ok! so QMC works TOGETHER with imap? I mean, when I'm satisfied with QMC lighting, I go back with imapping and the lighting will be the same only better? I thought QMC was a totally different and separate rendering system or method.

Percy: Thanks, I'll check out those threads.

[flipside]

No no!

QMC controls all kinds of threshold values etc for almost all vray render features. If you change values in QMC settings, it controls for example IR map calculation, area light shadows, blurry reflections etc...

Just read the help file on this one, it will get clear to you, I don't know how to explain it.