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View Full Version : Surface Baking Camera and Motion Blur??



Lorigosolo
10-26-2008, 09:22 AM
Hey Guys and Gals!!!

Simple and quick question, does the Surface Baking Camera work with motion blur?? If i want to bake my ilumination to a UVmap and Im using the spinning spotlights trick, my baked UV will not have soften shadows as the spinning trick will not work without the blur, right?

Any advice or trick that i could use to achive that??

Thanks in advance!! :thumbsup:

biliousfrog
10-26-2008, 12:40 PM
If you're baking illumination to save render times then use radiosity for the illumination.

The spinning light trick is generally used to fake GI in order to keep render times down.

Baking is usually used to 'store' GI so that it can be disabled from renders.

Personally, it seems a little strange to use spinning lights and then trying to bake that information when GI will usually give better results.

Lorigosolo
10-26-2008, 12:46 PM
Yep, I know that the spinning light trick is generally used to fake GI.

Forgot to metion that the reason why i need to bake the illumination to my model is because it will be used on a game engine, so i was trying to fake the GI and apply it to my model UVmap.

I agree with you that it would be a little weird to bake it when I could use GI to achieve better results when rendering directly in Lightwave!! ;-)

Paul Brunson
10-27-2008, 10:22 PM
umm...I think biliousfrog is right, if you're trying to bake lighting into a texture using Lightwave why not use real GI?

Regardless of how you light it (spinning light or GI) the final lighting gets saved into your texture by lightwave and you then load that texture with your game engine on to the object.

baking just adds whatever lighting you have in Lightwave to your model's textures. At that point the lighting info is simply stored as RGB values in your textured image.

biliousfrog
10-28-2008, 04:49 AM
yeah, I don't think that you quite 'get it'.

If you're baking the textures for a game it doesn't matter whether the GI render takes a day to finish, once it is done you'll never have to do it again...that's the point of baking!

Look at any modern computer game, HL2, COD4, the environments have been set up with realistic lighting and radiosity, had the lighting baked into textures and then loaded into the engine with very simple lighting. Once the textures have been created with the lighting 'baked in' you don't need to use GI anymore...you can turn off the diffuse and crank up the luminosity if you like and the textures will still look like they are being lit with GI.

So using spinning lights is a bit pointless for baking because the initial render times are not important, the final look is.

Lorigosolo
10-28-2008, 05:29 AM
Oki doki guys!! Will use GI instead of fake it with a dome of spining lights!! Im a Newbie on this matter!! Thanks for the inputs and help!! :thumbsup:

Mr Rid
10-29-2008, 09:20 PM
It may sound like an exaggeration, but every single time I use a significant LW feature for the first time, inside about 10 minutes I hit considerable bug or limitation that am baffled how no one else seems to have run into. This time its moblur with the Surface Baking Camera.

Motion blur inevitably introduces weird artifacting on any object in any scene I set up (9.3 and 9.5). Is anyone actually getting it to work?

looks as expected with 1-pass/no moblur
65264

with motion blur- the white is coming from the background color... & dont know where the dark shadow is coming from since trace shadows are off.
65265
any image or color in the BG winds up covering much of the rendered image. Can find no setting adjustments in the camera, object, or texture that make a difference.

Even a simple ball in a default scene has similar problems. BTW, the surface baking shader works fine with moblur, but has its own big limitation.

jameswillmott
10-29-2008, 09:31 PM
And you of course filed a bug report right? :)

(What's actually moving in your scenes, camera? Lights? Objects?)

Mr Rid
10-29-2008, 11:39 PM
And you of course filed a bug report right? :)

(What's actually moving in your scenes, camera? Lights? Objects?)

I run it by the forum first to see if I am just stupid.

I am moving any object on the Z with nothing else going on, just an otherwise default scene.

jameswillmott
10-29-2008, 11:53 PM
Why are you moving an object that you're baking?

Just curious, but I'm also going to test that here and see if I can get it to break like your example...

EDIT: Ok, it would seem that when the baking camera looks through the mesh it doesn't follow it if the mesh moves. Sounds like a bug...

Mr Rid
10-30-2008, 01:51 PM
Why are you moving an object that you're baking?

Just curious, but I'm also going to test that here and see if I can get it to break like your example...

EDIT: Ok, it would seem that when the baking camera looks through the mesh it doesn't follow it if the mesh moves. Sounds like a bug...

Currently using for Sas fur baking an animated creature. But may be anything with shadows moving over it that takes unneccasarily long to render otherwise, usually involving radiosity.

Am not sure what you mean by 'when the camera looks through the mesh.'

When I find these glaring issues in a well established feature, I keep wondering... am I really the first LW user ever to try the baking camera with motion blur?!

The surface baking shader will not save out an image sequence. It saves sequentially numbered images, but all the frames are just frame 1 repeated. And its much slower than the baking camera. But again am wondering how I can be the first person to ever try saving a sequence.

toby
10-31-2008, 01:16 AM
I'm on the "why are you rendering motion blur and baking at the same time" side of the fence - really not surprised they weren't worried about compatibility here. What effect are you trying to achieve?

But again am wondering how I can be the first person to ever try saving a sequence.
First time I've heard of it =)
But if you want baked lighting for every frame, you might as well just render a lighting pass with your regular camera and use it in comp, right? Probably faster than baking the whole texture every frame, plus re-rendering it mapped on the geo.

creacon
10-31-2008, 02:50 AM
We tried to bake several scenes using LW and in the end simply gave up.
One of the basic problems is that it is not actually a baking camera as you would expect from other renders (Modo has 2 ways of baking, but it has other problems that make the baking useless), it is an advanced camera that uses the object polygons as a camera plane (I would call it an "object projection camera" more than a surface baking camera.

This means that if you have other objects in the scene that they will show up in your baked textures too.

The one thing that saved us in this case was Kray, the developer understood what a baking camera is supposed to do and was a great help in solving problems.

creacon

biliousfrog
10-31-2008, 03:56 AM
Perhaps use the radiosity baking?...honestly, if you're using 9.5, I'd be surprised if loads of spotlights + motionblur + extra AA is faster than using perspective cam with 2 AA passes and interpolated FG.

I'm still really confused why people are trying to cut rendering times on baked scenes by using spinning lights...that's not what baking was created for!

What are you expecting to achieve by baking a sequence? You going to bake every frame to a texture so that you can re-render it all again...isn't that actually increasing the amount of work and render times rather than decreasing them? Why don't you just render the scene with motion blurred lights and forget the baking completely?

Bookman
10-31-2008, 01:23 PM
SB Cam almost allways gives me some sort of render error. Fortunatly I have an old copy of Microwave that still workes much better. :)

Mr Rid
10-31-2008, 05:40 PM
I'm on the "why are you rendering motion blur and baking at the same time" side of the fence - really not surprised they weren't worried about compatibility here. What effect are you trying to achieve?

Sas fur baking is the best example. Am working on furred creatures. Rendering fur with self shadows and receive shadows takes 3 hours a frame on a Mac Pro, at 1k with 5-pass AA. I eventually need 2k with at least 10 passes which will be over a day per frame to render!

But if I render the creatures without fur and save out a UV sequence with moving shadows baked in, I can then bring that color UV sequence into Sas and drive the fur color now with the shadows baked in to the fur without ever even having to trace any fur shadows. What took 3 hours a frame is literally now taking 3 minutes a frame!

Another interesting example was how I could generate the slime trail for this creature on the floor and wall by baking shadows and having LW load in the same sequence it is saving out.
http://www.box.net/shared/static/ao450o1wk8.mov

Mr Rid
10-31-2008, 06:11 PM
Another example I wanted mention was where I had to render a CG building exterior recently with a few moving shadows and radiosity but that was taking many hours per frame and was 700 frames long. Nothing was changing in the shot but the client kept noodling the camera move over and over which meant 2 days to redo each time (yes, it was approved each time, and we billed them each time it changed). I could instead bake the building and shadows and then re-render with different camera moves ad nauseum much quicker. So far, I can workaround motion blur, but I see no reason for it to not work.

toby
10-31-2008, 10:08 PM
Sas fur baking is the best example. Am working on furred creatures. Rendering fur with self shadows and receive shadows takes 3 hours a frame on a Mac Pro, at 1k with 5-pass AA. I eventually need 2k with at least 10 passes which will be over a day per frame to render!

But if I render the creatures without fur and save out a UV sequence with moving shadows baked in, I can then bring that color UV sequence into Sas and drive the fur color now with the shadows baked in to the fur without ever even having to trace any fur shadows. What took 3 hours a frame is literally now taking 3 minutes a frame!

Another interesting example was how I could generate the slime trail for this creature on the floor and wall by baking shadows and having LW load in the same sequence it is saving out.
http://www.box.net/shared/static/ao450o1wk8.mov
I see, pardon my line of questioning, I know tee-tee about hair. But do you need motion blur to render that shadow pass? And I thought the thing to do for hair was to never raytrace, but use shadow maps - really, I'm just curious, I almost never render hair, but I'd like to be prepared :)

Mr Rid
11-01-2008, 12:57 AM
I see, pardon my line of questioning, I know tee-tee about hair. But do you need motion blur to render that shadow pass? And I thought the thing to do for hair was to never raytrace, but use shadow maps - really, I'm just curious, I almost never render hair, but I'd like to be prepared :)

The neccessity of motion blur would of course depend on what you are rendering. Shadow maps are inaccurate and can have light showing up in places where it photorealistically shouldnt be. But again, it just depends on what you can get away with. I pretty much always use an area light or two and radiosity for any photoreal lighting. Sas forces you to use spots. Area lights can self shadow Sas but not cast or receive. Radiosity is too costly to render in Sas. So to get realistic shadow falloff you have to get creative with spinny lights or else bake a mesh with good area and radiosity lighting. Its also important to keep meshes and fur in the same lighting world. Have not had time to wrestle with FiberFX yet.

Mr Rid
11-01-2008, 10:07 PM
Oki doki guys!! Will use GI instead of fake it with a dome of spining lights!! Im a Newbie on this matter!! Thanks for the inputs and help!! :thumbsup:

I just noticed this post and wanted to clarify something I see some confusion about. Spinny-lights and light domes can be fine for faking radiosity-like shadows but will not recreate radiosity color bounce between objects- the color aspect seems occasionally overlooked. A light dome can match environment color and also cast spec that radiosity wont, but object colors wont bounce between each other which is much of the point of radiosity, beyond just soft shadows.