LM_2DMV gizmo in nuke 4.6

[NEO]

Have anyone tried this gizmo in shake 4.6? Can't really get it to work but wonder if i might be doing something wrong. I have connected the motionvector data to the MV side of the gizmo and the color data to the pipe side. But it doesn't seem like i get any "new" data out from it. Cause i guess it is supposed to be connected to vector blur... right?


or hey... something just struck my mind. from maya i rendered woth the option "realsmart motion blur vectors"... Maybe it should be set at SmoothKit. Hmm... Gona try that to. But meanwhile, all info is appriciated about this lil gizmo.

[NEO]

Hmm... It states that it should be RSMB-vectors. I took a deeper look into how that gizmo is built and it seems like something goes wrong in this lil expression node:

Expression {
channel0 {rgba.red -rgba.green -rgba.blue}
expr0 ((r-0.5)*width)/2
channel1 {-rgba.red rgba.green -rgba.blue}
expr1 ((g-0.5)*height)/2
channel2 {-rgba.red -rgba.green rgba.blue}
name Expression5
xpos 130
ypos 177
}

I have rebuilt the node tree and tested different settings and connections but havn't really gotten a good result.. I'm like :rollbaby:

[fr3drik]

Did you follow the instructions on this page to render out the vectors correctly?
http://www.impresszio.hu/szabolcs/MentalRay/lm_2dmvMayaFiles.htm

Then, in Nuke;

Pipe the CG footage into "Pipe" and pipe the rendered vector image into "MV".
Create the VectorBlur node (Filters) and set the uv channels to "uv". Then start by tweaking the multiply value.
Since your vector image most likely is linear, tick the box "linearize MV" in the LM_2DMV if things doesn't look right.

[NEO]

Heya Fredrik!

Yeah, the vector passes are ok from Maya. I use them in shake with real smart without probs. I will attach some pictures and screens in a while. Seems like I have missed something. Can't really figure out what though. Have you tested this gizmo in 4.6? Should be no prbs though since it seems like a pretty straight forward lil gizmo. =/


Did you follow the instructions on this page to render out the vectors correctly?
http://www.impresszio.hu/szabolcs/MentalRay/lm_2dmvMayaFiles.htm

Then, in Nuke;

Pipe the CG footage into "Pipe" and pipe the rendered vector image into "MV".
Create the VectorBlur node (Filters) and set the uv channels to "uv". Then start by tweaking the multiply value.
Since your vector image most likely is linear, tick the box "linearize MV" in the LM_2DMV if things doesn't look right.

[NEO]

So... Screenshot attached. This is just some simple test renders to test this out. Thought that the problem might had been in my original material but it works fine in shake. As you can see here the VectorBlur is pretty much at it's preset. Have tried different values for "add", as stated in the "mouse over" (-.5 or -127/255), but it just looks wrong. Have tested all different settings there is. Also tested to break the gizmo down in pieces but no luck there either, so far.

If I look at the LM_2DMV-node output in a viewer and just looks at the UV-channels, shouldn't I see something smooth and nice there, something similar to the vectorpasses. The second attached picture shows what I have there.

The cube in the picture moves from left to right and the sphere from top to bottom.

[NEO]

Mkay, I'vew been at it again. Looking at the first screenshot we see that it is almost working. SOme strange "stray lines" in it though. Dunno why they are there. Seems to me like some constant vector of like .5,.5 are added to them. Feels like the converted vectorpass ain't smooth enough or something.

And looking at the second screenshot one can see the roughness of the converted vectorpass. But maybe it's just the looks of it cause when measuring in it one can clearly see that there are loads of large negative values in the dark areas where there are supposed to be info.
And in the areas where there are supposed to be no info at all we have R: -480 and G: -270 (when measuring on the uv layer on the converted vectorpass, top left viewer).

And the biggest problem, as seen on screenshot 3, seems to come from chopped renderings. Dunno why the vector pass from Maya got chopped like that. Smells like rerender. =/

[fr3drik]

Do you have access to earlier Nuke releases?
I've used 4.5.27 and the LM_2DMV node with successful results. Unfortunately I don't have the time right now to try this with 4.6 but whenever I do, I'll post the results here.

[NEO]

Sweet man! Might be some user error to since I'm kinda new to nuke. I ended up mbluring it in shake instead with rsmb. No problems there.


Do you have access to earlier Nuke releases?
I've used 4.5.27 and the LM_2DMV node with successful results. Unfortunately I don't have the time right now to try this with 4.6 but whenever I do, I'll post the results here.

[ndeboar]

Hey,

Ive finally got the gizmo working. Play around with the multiply value, i set mine to .05 and that gives a really nice result. And just remember to set your MV to linear, and don't linearize in the gizmo.

My problem now is when i re-open my scene, the gizmo stops working and i have to re-install it. Why? Is there a trick to installing Gizmos? Im just going import script, but i have to re import it every time i reopen this scene. Arh!

Cheers.

Nick D
www.oasispost.com.au

[fr3drik]

There should be extensive info on how to setup your own environment in the manual PDF but this would be a quick way to make the gizmo load automatically upon Nuke startup.

Place the gizmo file (*.gizmo) inside of the plugins folder of your Nuke installation.

In your menu.tcl file, add this line:
menu "My Gizmos/gizmoDescription" "HotKeyHere" gizmoFileNameHere

Replace gizmoNameHere with i.e. LM_2DMV and if you'd like to specify a hotkey, replace hotKeyHere (or just leave it as this: "") and you should be set!

[ndeboar]

sweet, works a treat.

[ndeboar]

Hey,

Im having a few more troubles with this (hopfuly this is the last one!).

It's doing something funky with the alpha, the top one is just with .05 blur, the bottom is 1.
http://www.vfxtalk.com/forum/attachment.php?attachmentid=3488&stc=1&d=1178180278


Here's my motion vector, the scene has a sphere around it hence the vectors in the background:
http://www.vfxtalk.com/forum/attachment.php?attachmentid=3490&stc=1&d=1178180602


According too http://www.revisionfx.com/support/faqs/generalfaqs/motion_vector_alpha/ you are supposed to render the image with an alpha, now when i do that things get really weird:
http://www.vfxtalk.com/forum/attachment.php?attachmentid=3491&stc=1&d=1178180602


Any ideas?

Thanks guys,

Nick D
www.oasispost.com.au (http://www.oasispost.com.au)

[NEO]

I have not followed up so much on this since i got loaded with other work at work. =( I ended up mbluring my stuffs in shake and then reimporting it. For that time it felt like the safest move for me. I got an email from the author tday where he answered my questions. He have not tested it in 4.6 but he will do that shortly. I will point him to this thread. =)

One thought though... Why do you have the sphere set to "renderable" on the vector-pass-renderlayer? Wouldn't it be better to not add the environment sphere to that renderlayer? Maybe that helps?


Hey,

Im having a few more troubles with this (hopfuly this is the last one!).

It's doing something funky with the alpha, the top one is just with .05 blur, the bottom is 1.


Here's my motion vector, the scene has a sphere around it hence the vectors in the background:


According too http://www.revisionfx.com/support/faqs/generalfaqs/motion_vector_alpha/ you are supposed to render the image with an alpha, now when i do that things get really weird:



Any ideas?

Thanks guys,

Nick D
www.oasispost.com.au (http://www.oasispost.com.au)

[Diogo Girondi]

Hi All,

I'll be testing this with Nuke 4.6 in the following weeks and I'll let you all know. But for a quick glance on your MV pass Nick D I would say that they look a bit different from the ones I do here. Check if your channels are on the right place and make sure that your MVs are normalized. Since I use the lm_2DMV in XSI I couldn't say how this works in Maya.

Well when I get my hands on 4.6 I'll check if it's still working as it should.


Cheers,
diogo

[scorpes]

Hi all,, i am also having some trouble to get it to work. I am using 4.6 and i get weird diagonal motionblur, even without motion vectors?

Greetz Robbert

[Diogo Girondi]

Ok, LM_2DMV step by step.

Settings on the node

"Get MV from" drop down menu has two options "Reader" and "UV Channels". Reader will use the MV input to shuffle copy your Motion Vector pass channels to the UV channels of your stream. UV Channels will use the UV channels of your stream.

Unpremultiply Motion Vectors checkbox if checked will unpremultiply your Motion Vectors. Check this if your MV pass is premultiplied.

Linearize MV checkbox will linearize your MVs case they are in sRGB.

Using it

Connect the Pipe input to the stream that want to apply the vector blur or be affected.

If your Motion Vectors pass is loaded using a dedicated reader connect it to the MV input and set the node to get the MVs from Reader. Case your MVs are already on your stream (pipe) forget the MV input and just connect the Pipe input to your stream and set the "Get MV from" to UV Channels.

Check Unpremultiply Motion Vectors and Linearize MV case necessary.


Settings on VectorBlur

1. Set uv channels drop down to uv
2. You can play with the add values or leave them as 0, in my case using the recomended formula (-127/255) works fine.
3. Multiply, use the value that works best for you.
4. Offset, use the value that works best for you.
5. Grow bbox, use the value that works best for you.
6. Method set it forward, backwards won't give your good results.
7. Alpha select the alpha

This should be enough to make it work. But...there is always a but :) since I've made this gizmo with version 4.5.27 and I haven't updated Nuke to version 4.6.xx or newer I can't say how it's behaving.


cheers,