LWF, Color mapping and Animation

[pixelstudio]

Well hello vray people.

We got a bit of a problem here and i hope some of you guys are able to help us.
We are working on an animation, with moving objects and such. so thats to be considered.
Next we want to work in Linear workflow. (we used to not work in LWF)

So a couple of problems occur.

When rendering in LWF, you have to manualy set the diffuse color using the color correct plugin (yes ??? ) and if you check the 'input gamma' and set it to 2.2 the textures should be okey ?

We have made a couple of render test using several color mapping's.
as the client request he wants a 'Sunny' overall look.
We have been using a Direct light as our sun. but using the techniques above our colors look to washed out, or we lack contrast between light and shadow. so the overall look is bleeched. maybe some has some pointers that we can check out.

Next we have tried the vraysun/vraycam. we are wondering how this affects the render times. cause we are rendering around 10minutes of video (PAL 25fps) we have to render allot and time is very important.
So any1 who has worked with vraysun/vraycam in an animation project please describe the pro and cons... ???

Next and last we are gonna do some moving people, that requires a different render workflow (i have read the tutorial with the shpere helpers). does any1 know if that is much more work... ??

Well the best to you all!

Best regards,

Martijn aka PixelStudio

[Clifton Santiago]

The only reason to use the color correct modifier in LWF is if you are trying to match a specific RGB value. Otherwise, just adjust the color swatches so they appear "darker" so they appear correct in LWF renderings.

LWF should shorten your rendertimes because light falloff in the mid-ranges are more correct, causing your scene to appear brigter overall. This means you can use less light for the same non-LWF results, which in a GI rendering, means shorter render times.

As for you scenes looking washed out, I think I had those problems when I first started working in LWF, but after a couple weeks, I eliminated those problems by using less light and darker materials. I also usually add a Reinhard burn of about 0.5 to reduce hotspots.

10 minutes sound like a pretty short render time. In interior animations with dozens of light sources, I am often looking at 45 minutes to 2 hrs frame time on a dual dual-core opteron.

If you are having difficulties rendering your animation in the allotted time, try going to a commericial render farm. I prefer the "tended" farms where there is someone I can talk to. Also, make sure they understand your LWF and the proper way to save your image output so they don't screw up your gamma.

[glyph]

Clifton - I thnk Martijn means a 10 minute animated sequence not 10min per frame! -that's nearly a movie

[pixelstudio]

euh yes i mean around 7.5 minutues of video so that means :
(pal format)

7.5minutes * 60 = 450 second
25 frames per second * 450 seconds = 11250 frames

lets say if we render 2 minutes per frame

(11250*2) / 60 = 375 hours rendertime so around 15 days non-stop rendering.

So if can imagine if the frame render time goes to 3 minutes we render almost 24 days...... so frame render time are improtant


Still or colors look to washed out, alos using reinhard.
do you all edit the bitmaps / textures when working in LWF ?

[Clifton Santiago]

If you have your gamma settings of Bitmap files: Input Gamma = 2.2, you don't need to touch your bitmaps. That setting prevents your bitmaps from becoming double gamma corrected.

Like I mentioned above, unless you have a substantial render farm (i.e. 30 or 40 decent render nodes) you are not going to be able to render long animations in-house with GI (unless you have a long deadline). Go to a commercial render farm. Always factor in render farm expenses when giving the client a price estimate.

[tricky]

We've used vraysun/vraycamera in animation for some time now and have had very good results. For one thing, the controls are quite logical if you are used to real life photography. I don't think there is a render time penalty which is noce. Also, you can illuminate your scene by just the sun/sky and modify just the shutter speed/aperture of each camera without touching the sun/sky to get a good exposure on a per camera basis (obviously this is completely scene dependant and wouldn't hold up if you were going inside and outside!).

People? Well, thats a tricky one. To be honest, we have never done an animation with moving objects 'in scene' with GI. We have only comped in afterwards. I am therefore not sure how to successfully render with GI and moving people - would IMap and LC work????

[pixelstudio]

Hy people,

Here are some test renders to illustrate some of the problems we have. we try to get an sunny look (generaly meaning lots of contrast and vibrant colors)
But you can see for your selfs :

First two LWF



NO LWF << here is more contrast if you ask me .. ??

[Clifton Santiago]

You are most likely overlighting your LWF scene. Try turning down your environment lighting. You also need to make your color swatch materials darker to compenstate for the gamma (or put them inside a color correct modifier set to 2.2).

When I first switched to LWF I used to have problems with contrast, but after working with it for a while, I figured out how to compensate for it. The problem is as visualizers we have been lighting "incorrectly" prior to LWF. You need to re-learn the correct way to light a scene.

The whole reason for LWF is to be able to see the correct light falloff, particularly in mid-range values. For example, with LWF you can have an interior spotlight washing down a wall and have an exponential inverse decay, which is physically accurate. Without LWF, the light appears to falloff too quickly, so you have to change the decay to inverse or none to look "correct".

Take a look again at the "original" LWF article by Rob (he seems to have removed it from his own site):

http://www.highend3d.com/3dsmax/tuto.../vray/147.html

However, if you prefer to fight against the gamma curve, don't use it.

[pixelstudio]

Ahh thanks man, you'v been a good help!

I'll be trying more with LWF hehe

[pixelstudio]

Well it's getting better yay but i need to spend some time building the whole model

Here are some test renders :

[ene.xis]

there s something wrong with ur LWF use here.
atm if u want to apply(burn) the 2.2 gamma correction u just have to use this value in the gamma field on the color mapping rollout...if u use the .4545 +2.2 values i think ur double correcting ur render!

[pixelstudio]

well i think you are right hehe.

A other question,
Working in LWF you have to manualy adjust all diffuse colors using colorcorrect plugins (to get the correct gamma). seems logical.

How does LWF affect the diffuse color on the lights ? should i do something here (using a standard directional light) ?

[ene.xis]

it makes sense to me...
but u really should check Lele(aka studioDIM) s tutorials if u haven t allready!


http://www.chaosgroup.com/forum/phpB...=17824&start=0

[priad]

sure you need to