Very Computer

Righty ho,

This post is a follow up to one I just made about L[6] motion blur.  I'm
pretty sure I've never heard this done for LightWave, and I don't think it's
in L[6].

LightWave's renderer is great, and the way it motion blurs the scene is very
cool, despite being dead simple.   But don't you wish sometimes that you had
an alternative.

When I used to work on SoftImage we used a post process motion blur.
Basically you render your scene without motion blur and then use a
stand-alone program to analyse the scene file and work out a screen motion
vector for each pixel.  It then does linear motion blurs to each pixel and
generates motion blurred images.

It's dead simple and very, very cheap on render times.  It's great for
moving cameras because it doesn't have to render the scene 9 times to get a
whip pan effect, and if you're rendering in layers you can sometimes get
away without even anti aliasing on fast moving stuff.  Alright it totally
falls over on transparent stuff and reflections, etc, etc, but when you
think about it you don't need that stuff that much.

Does anyone know of a LightWave plug in to do this, or if it might be done
with L[6].  Could a programmer maybe tell me if such a thing is doable with
the SDK.  I have often thought the saving in render times could be worth the
cost of hiring a programmer to write it.

thanks for any advice,

ben

Quote:> Righty ho,

> This post is a follow up to one I just made about L[6] motion blur.
I'm
> pretty sure I've never heard this done for LightWave, and I don't
think it's
> in L[6].

> LightWave's renderer is great, and the way it motion blurs the scene
is very
> cool, despite being dead simple.   But don't you wish sometimes that
you had
> an alternative.

> When I used to work on SoftImage we used a post process motion blur.
> Basically you render your scene without motion blur and then use a
> stand-alone program to analyse the scene file and work out a screen
motion
> vector for each pixel.  It then does linear motion blurs to each pixel
and
> generates motion blurred images.

> It's dead simple and very, very cheap on render times.  It's great for
> moving cameras because it doesn't have to render the scene 9 times to
get a
> whip pan effect, and if you're rendering in layers you can sometimes
get
> away without even anti aliasing on fast moving stuff.  Alright it
totally
> falls over on transparent stuff and reflections, etc, etc, but when
you
> think about it you don't need that stuff that much.

> Does anyone know of a LightWave plug in to do this, or if it might be
done
> with L[6].  Could a programmer maybe tell me if such a thing is doable
with
> the SDK.  I have often thought the saving in render times could be
worth the
> cost of hiring a programmer to write it.

> thanks for any advice,

> ben

It's certainly -doable- with the SDK, but you'd have to analyze the
scene file yourself.  There is no built-in function I'm aware of called
"getVelocityOfPixel", or even "getVelocityOfVertex", though the latter
is computable and you could do it with a displacementmap plug, then blur
the stuff with an imagefilter provided you load the object with, say,
objectman and compute which pixels are covered by what polygons
yourself.  That involves transforming the vertices to screen space
(easy) and rasterizing the polygons yourself into your own z-buffered
velocity buffer (yuck)

So, doable, but not trivial.  But hey, in L6, you might be able to do
the whole thing with a shader + image filter, so you could compute
velocities in the shader.  I dunno how much object info you get in the
shader, but if it's sweet you could compute velocities right from there.
 Worst case scenerio you'd also need a dispalcement map plug, but I have
a feeling that plugs will be more integrated in L6, so it might appear
to the user as just one plug.  We'll see...

- GLYPH

Sent via Deja.com http://www.deja.com/
Before you buy.

Quote:>>blur the stuff with an imagefilter provided you

load the object with, say,
objectman and compute which pixels are covered by
what polygons
yourself.  That involves transforming the vertices
to screen space
(easy) and rasterizing the polygons yourself into
your own z-buffered<<

Doesn't MAX have a toggle for "real" 3D or faked
2D motion blur?  I think I read that somewhere.
The fake blur was supposed to look as good for
most purposes, but renders way more quickly.

---------------------------------------------

http://www.destinyimages.com/profiles.html
http://www.mp3.com/PANUCCI
http://www.mp3.com/PeeSiblinz
---------------------------------------------

Hmm.. maybe I'll write the plug-in, then.

- GLYPH

Sent via Deja.com http://www.deja.com/
Before you buy.

If you like to do any compositing,  After effects has a couple
features that can help you.
1)It has the same photoshop plugin your used to
2)If move or distort a single layer you can choose to apply
   a motion blur.

Doesn't WaveFilter and one of the Pontari image pixel plugins do this
already?

Ivan

Wavefilter does post-process DOF.  I don't remember if it does motion
blur.  DOF is easy to implement, cause you can do it right from the
buffers that an image filter gets.  Motion blur requires a whole lot
more work, so it's not too likely that it's been done for LightWave.  I
hope that it *has* been done, because I'm kinda busy right now...

- GLYPH

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