controlled motion blur

[jeremybirn]

Most compositing programs (After Effects, Shake...) can do that, animate something's position and then render frames with motion blur on that motion.

In Photoshop you could define a custom brush for the shape of the highlights and then stroke a curve with it, but then you'd still want to blur or fade out the ends and paint some other glow and blur into that layer.

-jeremy

[samel]

Most compositing programs (After Effects, Shake...) can do that, animate something's position and then render frames with motion blur on that motion.

In Photoshop you could define a custom brush for the shape of the highlights and then stroke a curve with it, but then you'd still want to blur or fade out the ends and paint some other glow and blur into that layer.

-jeremy

..umm, yeah i know.. let me rephrase my question..

you have a still image of a road/landscape and a still image of a car.. they are matched in angle and lighting. the car image goes on the bg. I need to make it look as if the image was shot from a rig mounted on the car while it was travelling nicely along the road.. hence, the car needs to be sharp and the bg heavily motionblurred.. normally you would just throw a zoom-blur on the bg and voila.. but i anticipate running in to trouble if the path of the "moving" car is curved..say the bg shows that the car has just moved around a sharp bend or something..
see attachment..

//s

[Whipyo]

I have wanted this for years.

There is nothing on the market that can do this within photoshop.

If you have the patience (and time), you can do heaps of different radial blurs where the radial center is in slightly different positions and then attempt to mask various parts of your image together to get the look you want. It can be pretty messy though and the results vary.

If the radial blur produces a lot of streaks, its usually best to gaussion blur the streaks a bit because when you stitch together your varoius blurs, it really stands out that the streaks are not lining up with each other.

I believe that painter has a motion blur tool where you can define the shape of the motion blur according to cursor movements. Not quite what you want but could be something to investigate as a tool to perfect the technique.

[samel]

thanks for the photoshop workaround Whipyo..
that might do the trick..
will also look into that painter-tip..

i thought of a really messy way to do it.. actually it might be one of the longest
ways around a problem ever taken..

block out your still bg in maya..
try to guess how the car/cam-rig should have moved if it had been for real
and animate your camera..
render a post m-blur with the lm_2DMV mental ray vector shader
now you have "custom-painted" the motion you want to apply to your bg with
motion vectors.. smack them on the bg with RSMB or smoothkit in after-effects or shake
might work.. might look like crap..
+there's gonna be trouble running hi-res (300dpi) stills through maya/aftereffects/shake

anyway.. that is just ridiculuous..:D
if anyone has more tips it would be much appreciated..

i cant believe no-one's ever written a plug-in that does this..
as stated, people must have wanted this for years..

//s

[Whipyo]

I was going to mention the 3D method but I wasnt sure if you had access to a 3d app.

I have done something similar in cinema 4d. I cloned out the car and blocked out the road, wall and trees using simple geometry (my shot had trees in it). I used my actual image as textures and then animated a camera with scene motion blur (lots of motion blur to cover the simplistic geometry). It took ages to manually work out the camera zoom. Dropped this back into photoshop and comped the car back on top.

The only tricky bit was then getting the car shadows right. It didn't turn out too bad.

As you say, its a bit unpractical to do in hires.

Anyway, good luck with it all. If you get a decent result, post it here.

Whipyo

[pgraham]

For a simple curve, shear the image (Filter>Distort>Shear) so that the road becomes straight. Then do radial (zoom) blur or motion blur. Then shear the image back to the original curve. Unfortunately the shear dialog doesn't let you enter numbers for the control points, so you'll just have to eyeball it.

[samel]

hey Whipyo, good to hear someones's actually gone down that road before..
maybe i'll give it a try.. will post if it turns out alright..


pgraham..
dude, "shear the image so the road becomes straight" sounds alot like press the magic-button.. :D kidddin.. but i messed around with it and i can sorta "undo" curvature
so a line arcing from bottom-left to top-right gets (more or less) linearly diagonal from b-left to t-right..which would work fine to apply motion blur to..i couldnt unshear it back to my original curvature though..or maybe with some tweak, but not without altering the image..and i'm not sure if this technique is completely undestructive since your actually pulling stuff around rather incatiously..
thanks for the tip though, i'll poke around with it some more..

//s

[pgraham]

i'm not sure if this technique is completely undestructiveYeah it's most definitely completely destructive, duplicate the layer and work from the copy. I was just throwing that out there since the other ideas seemed relatively involved.

edit: found something... you can smudge along a path. Create the path you want to blur along, choose the smudge tool, pick a big solid brush and set the strength pretty low. Click the stroke path button in the paths palette. It's not perfect but at least it's easy to define the direction.

[little5points]

ahem...

http://www.andromeda.com/main/velociraptor.php

[Whipyo]

http://www.andromeda.com/main/velociraptor.php (http://www.andromeda.com/main/velociraptor.php)

I tried to download the mac demo. It seems that there is no OSX version - only classic.

Copied from the site:

Velociraptor Filter v2.2
Windows:
Adobe Photoshop 5.5 up to 7(classic mode only/9.x) - WHAT THE?
Adobe Photoshop Elements 1.0 and up
Corel Photopaint 7 and up
Jasc PaintShop Pro 5 and up
Adobe Premiere 4.2
Picture Publisher 6

Mac:
Adobe Photoshop 5.5 and up
Adobe Photoshop Elements 1.0 and up
Adobe Premiere 4.2
Color It 3.2


Where they say (classic mode ony/9.x) for the windows version they obviously mean for the mac platform. The demo installer I downloaded was definately classic only. So if you are on a mac and use OSX dont even bother with this as you need to give them your email to try the classic demo.

If any of you PC people play around with this, I wouldn't mind seeing the results.

[little5points]

Unfortunately, there aren't many results to see. It only lets you generate a preview within the GUI...not even a water-marked image :(

It definitely gives you a lot of control, although it takes some tweaking. I didn't see anything that would let you create you own path though. It's easy to create arches, waves, etc.

[samel]

officially the suckiest UI..but this might be the best we get..with the arc option, the x and y stretch, intensity and angle i think i managed to match the mb in the attached mercedes image i posted earlier..hard to tell working on that absolutely tiny preview..and of course i cant post anything here..it would have been nice to have the ability to draw your own path, but generally an arc is what you want..

thanks little5points for sharing..

//s

[pixelchemist]

simple solution.... copy what you want to blur

paste to illustrator

use evelope distort to straighten it out...

copy it

bring back into ps as a new document

motion blur it

copy it

paste to illustrator

back to photoshop

grab your original

paste it into illustrator

take your straightend and blured image drop the opacity and put it on top of the original

use envelope distort again to match it to the original....

bring it back to 100% opacity

copy it

discard the illustrator doc

paste it into your original photoshop document

blend it in... and your good to go

[little5points]

or if you have CS2 you could do a motion blur and then use the Warp transformation to bend your motion blur

[pixelchemist]

cs2's warp is very limited compared to what i described...

[Jack Youngblood]

The Lens Blur might be of use. using it you can selectively blur through a grey scale channel.

[little5points]

cs2's warp is very limited compared to what i described...

I don't understand. What's the difference between using Illustrator's Envelope tool and PS's Warp tool other than the ability to add more mesh points in Illustrator? I was able to create a nice sweep using the Warp tool without having to go back and forth between 2 apps.

What am I overlooking?

[halo]

nothing, just what you just said...the ability to add more points.

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