Hardware Particles With Dof

[il_fabbro]

Hi guys,

I'm just finishing a big (for me) work where I have to composite software render (Maya render) with a hardware particles footage. I have an animated Depth of field camera on software and I've just realized that the particles will not sit inside that effect. I've serched up and down here and there but didn't find nothing about. Anyone clever here knows how to workaround this?
Maybe use a Zdepth "shaped" bay the Dof effect and use that in After Effects? I suspect that's tha way but really don't know how to achive it...
By the way, it's a pleasure to be here

il_fabbro

[joojaa]

You can do it in post yes. Theres a few different ways tough and they are to use very small sprites or jittering camera about the focal and then multi sampling motion blur.

Tough i do suggest you ditch idea of using AE for this. As it just does not have the tool repertoire to do good 3d comp. Its adequate, but mainly aimed for motion graphics.

[il_fabbro]

QUOTE(Joojaa @ 09/20/07, 08:14 AM) [snapback]273519[/snapback]
You can do it in post yes. Theres a few different ways tough and they are to use very small sprites or jittering camera about the focal and then multi sampling motion blur.

Thanks for reply but...
erm... sorry man, I can't get a clue of what are you saying here... have I to sobstitute my particles with small sprites for doing what? what's about "jittering camera about the focal" and "multisampling motion blur", I'm not sure if these are tecniques used in Maya or in a post application, and not even far to understend how to actually do that
Could you please try to explain these concepts?
But whatever tecnique you're talking about, think that I alredy have my animated Depth of Field on the cameras (actually 8 scenes) and don't want to throw that or to sobstitute with motion blur, nor I can sobstitute my Maya DOF with a post DOF.

QUOTE(Joojaa @ 09/20/07, 08:14 AM) [snapback]273519[/snapback]
Tough i do suggest you ditch idea of using AE for this. As it just does not have the tool repertoire to do good 3d comp. Its adequate, but mainly aimed for motion graphics.

Yeah you're probably right but for now I have this and have to deliver that work in a few days. I'll probably try Nuke for future works, since I'm not particulary fond of AE..

[il_fabbro]

In a few words, what I'm trying to do is extract some type of channel used to make the DOF effect in Maya and use that in AE to achive the same effect for my hardware render particles. Is that possible?

[joojaa]

QUOTE(il_fabbro @ 09/20/07, 02:19 PM) [snapback]273536[/snapback]
Is that possible?

Yes, but you need to render the particles 2 times because AE in its infinite wisdom does not support real Z channels. I still suggest you do the blur in maya with the first of above methods it is both faster to do and looks better!

[il_fabbro]

QUOTE(Joojaa @ 09/20/07, 01:50 PM) [snapback]273541[/snapback]
Yes, but you need to render the particles 2 times because AE in its infinite wisdom does not support real Z channels. I still suggest you do the blur in maya with the first of above methods it is both faster to do and looks better!

Bad news.. AE don't support Z
I still don't understand what is that "method" you're talking about. Take my particles, give it sprites (of which image?). It doesn't get sense to me
Is with this method my DOF wasted? Because... blur ain't depth of field, I can't _sobstitute_ one with another...

[joojaa]

QUOTE(il_fabbro @ 09/20/07, 03:11 PM) [snapback]273544[/snapback]
(of which image?).

A revolve of a half gaussian bellcurve, (do this open photoshop make a linear gradient balk to white, smoothness 0 in square image convert it to polar cordinates use curves to make the distribution, gaussian blur a fwww times make this a alpha channel, paint it all white, the write a ecpression to control pp size by mag(cam.position -particle.pos) times a linear function to lookup dof)

[gwelch]

Hi Fabio,
A simple solution that has worked for me, install "particleHWShader.mel"...I can email it to you if it is not on Highend3D.
Run script, then type in your camera name, partilce name, and choose "Depth with Focus" for R G B channels. A locator is created, and your HW particles are now pure white at the locator center and fall off to black. Adjust the fall off distance by selecting the new locator and changing the Focus Max Distance.

Now make the locator follow your camera and animated DOF.
Depending on how you animated your SW DOF (with a camera rig or using a standard maya camera), you can constrain the locator to your camera (you might need to group the locator first and then constrain the group, this way you can shift the locator position inside the group and/or make an expression to match the animated DOF distance.

Now HW render particles over black...Import into AfterEffects, use the compound blur effect, select invert, name these HW images as the source for the blur.

G

QUOTE(il_fabbro @ 09/19/07, 03:53 PM) [snapback]273513[/snapback]
Hi guys,

I'm just finishing a big (for me) work where I have to composite software render (Maya render) with a hardware particles footage. I have an animated Depth of field camera on software and I've just realized that the particles will not sit inside that effect. I've serched up and down here and there but didn't find nothing about. Anyone clever here knows how to workaround this?
Maybe use a Zdepth "shaped" bay the Dof effect and use that in After Effects? I suspect that's tha way but really don't know how to achive it...
By the way, it's a pleasure to be here

il_fabbro

[il_fabbro]

QUOTE(Joojaa @ 09/20/07, 03:09 PM) [snapback]273552[/snapback]
A revolve of a half gaussian bellcurve, (do this open photoshop make a linear gradient balk to white, smoothness 0 in square image convert it to polar cordinates use curves to make the distribution, gaussian blur a fwww times make this a alpha channel, paint it all white, the write a ecpression to control pp size by mag(cam.position -particle.pos) times a linear function to lookup dof)

That's circa a blurred circular ramp, isn't it? But why should I use such a sprite instead of my multi point particles, that is not distance sensitive too? What's the meaning of this related with the expression you said and my dof? Sorry I'm trying to "track" you in your cryptic answers but I'm still too young in Maya. I can just catch a glimpse of your "methods".
Thanks for that, your time and all, but can you connect a thing with the other and explain what to use for what and in wich way? I'm not trying to make you do my work but only to understand what you're saying.

[il_fabbro]

QUOTE(gwelch @ 09/20/07, 04:14 PM) [snapback]273557[/snapback]
Hi Fabio,

Lol.. my name is il_fabbro that means the_blacksmith. My real name is Lorenzo not Fabio

QUOTE(gwelch @ 09/20/07, 04:14 PM) [snapback]273557[/snapback]
A simple solution that has worked for me, install "particleHWShader.mel"...I can email it to you if it is not on Highend3D.
Run script, then type in your camera name, partilce name, and choose "Depth with Focus" for R G B channels. A locator is created, and your HW particles are now pure white at the locator center and fall off to black. Adjust the fall off distance by selecting the new locator and changing the Focus Max Distance.

Now make the locator follow your camera and animated DOF.
Depending on how you animated your SW DOF (with a camera rig or using a standard maya camera), you can constrain the locator to your camera (you might need to group the locator first and then constrain the group, this way you can shift the locator position inside the group and/or make an expression to match the animated DOF distance.

Now HW render particles over black...Import into AfterEffects, use the compound blur effect, select invert, name these HW images as the source for the blur.

G

Yeah, I'm trying it out. Just.. BIG thankz Gwelch!!

[il_fabbro]

QUOTE(gwelch)
A simple solution that has worked for me, install "particleHWShader.mel"...I can email it to you if it is not on Highend3D.
Run script, then type in your camera name, partilce name, and choose "Depth with Focus" for R G B channels. A locator is created, and your HW particles are now pure white at the locator center and fall off to black. Adjust the fall off distance by selecting the new locator and changing the Focus Max Distance.

Now make the locator follow your camera and animated DOF.
Depending on how you animated your SW DOF (with a camera rig or using a standard maya camera), you can constrain the locator to your camera (you might need to group the locator first and then constrain the group, this way you can shift the locator position inside the group and/or make an expression to match the animated DOF distance.

Now HW render particles over black...Import into AfterEffects, use the compound blur effect, select invert, name these HW images as the source for the blur.

G

Since I have my camera DOF animated through a Distance Tool with the 2 locators one parented to the camera and the other driving the distance, I've parented the new created locator with my focus distance locator. That seems to be very comfortable... but:
I've also a Multiply/Divide node, since my camera is scaled down, to accord the two values for Focus Distance (the real distance and the value needed for dof).

So I have to pass the three attertibutes used in the expressions (FocusDecayRate, FocusMaxDist and FocusRange) throgh others Multiply/Divide nodes to preserve proportions too? I've done so.
But but but the main problem that I have is that my particle object is scaled down! It isn't truly scaled (the bounding box is the same) but the opacity seems to cut out it. And there's no data on the opacity!!!
I'm going _mad_ #_#

[il_fabbro]

Sgraaaa that was a pucking CONSTRAINT, not a PARENT relationship...
Thanks I think I'm reaching there slowly

My last problem now is that I see my whited particles in focus in the preview but when I go rendering in Renderbuffer they seem to lack opacity at all.. All the screen black That's most probably because of the nature of multypoint particles that tends to be more visible when stacked one behind the other. Do somone know how to boost the opacity of the multi points without touching the multi-count or pixel size (which I can't). That's seems a _big_ problem because I cannot use the OpacityPP or per Object (the last one don't even work.. ) cause I have to respect the smoothed opacity created by the expression. Ouch!