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View Full Version : FPrime + Real camera lens = real DOF?



The Dommo
08-26-2009, 09:08 AM
Does anybody know if rendering DOF in FPrime, with the newish real camera lenses results in renders with nice hexgonal / pentagonal or whatever shape bokehs etc?

Mid project now, so can't do tests myself, but interested to know for a job we're quoting on - so if anybody already knows, please shout!

Thanks :)

Panikos
08-26-2009, 09:43 AM
You will definitely have the Lens Distortion of the Real Lens but I dont think you will get Hexagonal bokeh. FPrime DOF follows its own course.

The Dommo
08-26-2009, 03:32 PM
Ok thanks, will have to give it a try soon. Also keeping an eye on the depth of field thread here, using XDof...

moussepipi2000
08-26-2009, 03:44 PM
fprime doesn't respect the diagrams side of lens... i have just test it now.

lw give me a 5 side polygon at the render
and fprime give me a simple circle :(

Panikos
08-26-2009, 04:07 PM
Not only that
FPrime renders depth of field in Reflections and through refractions, something that LW does not

jameswillmott
08-26-2009, 04:43 PM
Not only that
FPrime renders depth of field in Reflections and through refractions, something that LW does not

Which version of LW are you talking about? LW 9.x uses raytraced DOF, it can't NOT render DOF through reflection and refraction. Sample attached showing true DOF in the mirror.

The Dommo
08-27-2009, 09:35 AM
Thanks for the input. I hope FPrime will one day respect the diaphrams of the LW lenses - this would be freaking awesome.

biliousfrog
08-27-2009, 09:48 AM
Best bet is still to do DOF in post

The Dommo
08-27-2009, 11:44 AM
which leads us back to the Depth of Field thread also being discussed!

Panikos
08-28-2009, 12:32 AM
Which version of LW are you talking about? LW 9.x uses raytraced DOF, it can't NOT render DOF through reflection and refraction. Sample attached showing true DOF in the mirror.

My friend. Your image doesnt illustrate what you are saying.
Show me a rendered mirror and instead of focusing on the mirror polygon, focus on the mirror content

jameswillmott
08-28-2009, 12:45 AM
My friend. Your image doesnt illustrate what you are saying.
Show me a rendered mirror and instead of focusing on the mirror polygon, focus on the mirror content

That's exactly what I did show, I focussed on the content. The content is crisp, but if you look at the edges of the mirror ( where the room widens out ) you can see they are clearly blurred...

Panikos
08-28-2009, 01:03 AM
I am sorry. You dont understand.
Put 100 balls, put a mirror to reflect them and focus only on one mirrored ball and have the rest 99 blurred. All these in a reflection.

jameswillmott
08-28-2009, 01:21 AM
I am sorry. You dont understand.
Put 100 balls, put a mirror to reflect them and focus only on one mirrored ball and have the rest 99 blurred. All these in a reflection.

To suggest I don't understand is a bit condescending...

(sigh)

A mirror, and some balls. One real ball and one mirrored ball are in focus, the rest are blurry. Both Fprime render AND LW render attached. They are virtually identical in their treatment of DOF.

LW's raytracing cameras can't get DOF wrong, they don't know if they are looking at a reflective surface or not, they just trace rays according to simplified physical laws. The component of the camera SDK that deals with DOF, only offsets the ray origin according to a virtual lens. That's all. Not checks for what surface you're hitting, it just calculates a ray direction per pixel. FPrime uses the SAME RAYS as LW does to render DOF through the raytrace cameras. Fprime gets it right, LW gets it right.

Right?

Whew.

biliousfrog
08-28-2009, 01:35 AM
My friend. Your image doesnt illustrate what you are saying.
Show me a rendered mirror and instead of focusing on the mirror polygon, focus on the mirror content

It does because the ball reflection is sharp where-as the ball itself is blurred.

Panikos
08-28-2009, 01:37 AM
Ok, I did a fast test. Perspective Camera does respect mirrors. Classic Camera does not.
Although your images arent the most suitable :P
Apologies for the misinterpretation.

jay3d
08-28-2009, 01:49 AM
I am sorry. You dont understand.
Put 100 balls, put a mirror to reflect them and focus only on one mirrored ball and have the rest 99 blurred. All these in a reflection.

Why not try it yourself, and show us the result?

it seems that u didn't worked in LW enough to know it's capabilities.

Panikos
08-28-2009, 01:54 AM
I've been using LW from 5.0 and later. DOF in reflections is something very rare or something unnoticeable.
"Knowing LW" is something very vast. Its very difficult to keep track of all the changes made.
Generally speaking, my principal rendering engine is FPrime unless I need Sasquatch or Volumetric Lights.