Vray Multilight VR?

[skogskalle]

right... this is probably close to impossible, or maybe even just alot of silly gibberish =) but I think its a cool idea so here we go anyways... :

havent used maxwell at all myself, so I dont know exactly how it works, but from what Ive heard I understand it has something called "Multilight" which enables you to change the light multipliers and see the result in realtime in your finished render. (so I guess its possible to for example turn down the sun/skylight to 0, and turn up all interior lights to change the scene completely from a daylight render to a nighttime render)

did I get it right so far, or ?

first of all, would this be possible to implement in Vray? I mean setting up the whole scene in scale, and using correct values for all lights. Hit render, and (after alot of time) end up with an image where we can play around with all the lights in realtime.

second, and this is the cool, and probably tricky, part. What if we could use this "multilight"-render and export it as a kind of dynamic textures to be used in some VR realtime program.
Dont know if I make sense here... but what I want is to be able to (in realtime) walk around in my perfect render, and be able to turn on/off all the lights in the scene.
This would give a whole new sense of realism to VR-presentations.....

so... is this totally impossible or just very very hard to do?

best regards
Kalle

[instinct]

a problem that springs to my mind with this is that vray is sampling adaptively amongst other things by brightness. Bright areas get more samples then dark areas. Hence if you crank up the lights the parts that were dark before will be undersampled.

Thorsten

[skogskalle]

i see... is this true even when using PPT mode (not adaptive ppt, the regular one)

/k

[joconnell]

You can do this type of thing using any compositor that supports floating point colour - have a look here for a bit of an idea how. http://www.joconnell.com/view.php?ca...rticle&view=19

[skogskalle]

hmm cool I didnt know that.

so what we need to be able to bring this into a VR environment would be support for layered hdr-textures? And the ability to blend these layers from within the VR presentation... (turning on/off lights) Is there any VR program out there that supports this today? Or would all the different hdr-layers simply take up too much memory for this to be an option?

[joconnell]

I'd say it would be quite heavy alright - percydaman did an animation where he faded between renders with different light setups that would achieve a lot of what you want - the halflife 2 and a few other games engines do what you want.

[percydaman]

indeed I did, but Im not all sure if its in the same vein of whats being proposed here.

[skogskalle]

- the halflife 2 and a few other games engines do what you want.

nice! but as far as i know source and other topshelf game engines cost a small fortune... and are you sure that source supports layerd hdr images as textures? I know it uses a hdri image for the sky, but Im not too familiar with the engine...

percydaman - could you please post a link to your animation? (if its still available somewhere...) Id like to see it!

Thats really cool that it works with stills anims. I guess Ill have to go and get me a good post-production program...

But just too be sure you understand what I was after in the first place. (sorry if im just repeating myself here)...
Think of a VR environment where all the objects have baked textures. This is easily done in max/vray today and looks great but creates a static VR environment.
If all those textures on all the objects were layered HDRIs (rendered at different lightconditions, as described in joconnels tut above) and you could change the strenght of each layer from within the VR presentation that would mean you could turn lights on/off in realtime.

/k

[studioDIM]

Well, unless you plan to show different exposures per lighting condition, you might just as well use LDR images with a nice visible range.
And "swap/fade" differently lit VR environments/baked textures when the user makes a selection.

Lele

[percydaman]

- the halflife 2 and a few other games engines do what you want.

nice! but as far as i know source and other topshelf game engines cost a small fortune... and are you sure that source supports layerd hdr images as textures? I know it uses a hdri image for the sky, but Im not too familiar with the engine...

percydaman - could you please post a link to your animation? (if its still available somewhere...) Id like to see it!

Thats really cool that it works with stills anims. I guess Ill have to go and get me a good post-production program...

But just too be sure you understand what I was after in the first place. (sorry if im just repeating myself here)...
Think of a VR environment where all the objects have baked textures. This is easily done in max/vray today and looks great but creates a static VR environment.
If all those textures on all the objects were layered HDRIs (rendered at different lightconditions, as described in joconnels tut above) and you could change the strenght of each layer from within the VR presentation that would mean you could turn lights on/off in realtime.

/k

Here's what I did:

http://www.arnoldimaging.com/spurcell/SS360.wmv

[skogskalle]

Thanks percy, I remember that one... Its really cool!

is it all Vray? Or are some of the furniture photos or something? They look very real.

[GALACTUS]

I dont know how the mawell version works, but from the video it appears as if.... You have a menu with all your scene lights listed with sliders for intensity control and as you move the sliders the intensity on the individual lights you are changing affect your rendered scene in realtime like when you use the effects section in max and you switch interactive on.

There is a video showing this on their web site in the gallery/video section at the bottom the thumbnail has the interface with a red sphere.

I have to say that it would probably be very slow on a large scene with lots of geometry or lights, as I am assuming all that info is buffered.

[joconnell]

I'd say it's doing fuck all aside from keeping each light as a seperate render layer and then allowing you to change the brightness of each layer - effectively just controlling the opacity of a 2d layer that contains the contribution of each light. Admittedly a nice idea but it's not exactly lpics...

[percydaman]

Thanks percy, I remember that one... Its really cool!

is it all Vray? Or are some of the furniture photos or something? They look very real.

thanks but its all 3d except for some of the plants. those are opacity mapped planes with photos.