Introduction to Maya - Rendering in Arnold
This course will look at the fundamentals of rendering in Arnold. We'll go through the different light types available, cameras, shaders, Arnold's render settings and finally how to split an image into render passes (AOV's), before we then reassemble it i
# 1 19-10-2003 , 02:43 PM
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Depth of field

Can someone tell me why i get these really jagged edges when i use DoF on camera.


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# 2 19-10-2003 , 04:58 PM
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Could you post some examples and what settings did you use?


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# 3 20-10-2003 , 02:12 PM
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Here you go. My settings where ,

Perspective camera DOF set to
Dist focus 10
F stop 9.85
Region 1

Maya Renderer
640 x 480
Anti alias Production
Highest quality

All object is scene are Nurbs
Tensselation set to Highest
U 8
V 8

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And after calming me down with some orange slices and some fetal spooning,
E.T. revealed to me his singular purpose.

--TOOL, 10,000 Days---

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# 4 20-10-2003 , 02:15 PM
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Close up

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And after calming me down with some orange slices and some fetal spooning,
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--TOOL, 10,000 Days---

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# 5 20-10-2003 , 02:16 PM
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I can correct this in mental ray but maya renderer gives me this. anyone know what it is and how to fix?


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And after calming me down with some orange slices and some fetal spooning,
E.T. revealed to me his singular purpose.

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# 6 20-10-2003 , 02:19 PM
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I just tried upping my Anti Alias samples to 5 8 and 9 but diesnt seem to help

Tried 20 samples and 20 max shading, still there.


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And after calming me down with some orange slices and some fetal spooning,
E.T. revealed to me his singular purpose.

--TOOL, 10,000 Days---

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# 7 20-10-2003 , 02:36 PM
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Hmm... have you played with the near/far clipping planes of the camera you're rendering through? Or perhaps some other image format which has 16 bits per channel instead of 8?


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# 8 20-10-2003 , 02:59 PM
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The image is rendering that way no matter what i save it in. THe only conclusion is that its one of my maya settings. I can correct the problem in mental ray render so but i cant figure out how to fix it in maya renderer.


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And after calming me down with some orange slices and some fetal spooning,
E.T. revealed to me his singular purpose.

--TOOL, 10,000 Days---

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# 9 20-10-2003 , 06:36 PM
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I think I know why this happens. Maya's renderer does not anti-alias the Z-Depth channel, which is used for the DOF blur. Maybe mental ray anti-aliases it and that's why you get better results. Anyway you could render your images without the DOF but saving the Z-Depth channel in the files. Then do the DOF in post but blur/anti-alias the z-depth a bit before.

Here's what the z-depth looks like directly from maya's renderer.

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# 10 20-10-2003 , 10:15 PM
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Does anyone know of a way to get to that z-Depth channel in After Effects? I've tried researching many docs, and posting in After Effects forums, but have never found an answer.

# 11 20-10-2003 , 11:30 PM
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Originally posted by kbrown
...you could render your images without the DOF but saving the Z-Depth channel in the files. Then do the DOF in post but blur/anti-alias the z-depth a bit before.

Here's what the z-depth looks like directly from maya's renderer.


Man.. did you ever loose me there.. LOL .

Ok after i figure out how to extract an image that looks like yours i blur it in photoshop? then how do i use that to Blur DoF my maya file?


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# 12 21-10-2003 , 12:19 AM
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Lol. I just read what i wrote and shaked my head user added image

Anyway, you're kind of on right track with what you suggested yourself. Only that I'd use after effects instead of photoshop. I'll play with this tomorrow more. It's too late right now :/


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# 13 21-10-2003 , 02:28 AM
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k thanks, im looking forward to your reply.


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And after calming me down with some orange slices and some fetal spooning,
E.T. revealed to me his singular purpose.

--TOOL, 10,000 Days---

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# 14 21-10-2003 , 04:59 PM
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Alrighty. Starting with a new scene and default settings in Maya do the following:

Create two nurbs spheres @ 1 1 -5 and @ -1 1 5
Create a nurbs plane @ 0 0 0 and scale it up by 25
Create camera @ 0 1 15
Select Display->Camera/Light Manipulator->Clipping Planes (so that you can see what the next few settings do)
Uncheck the camera's "Auto Render Clip Plane
Set the cameras near clipping plane to 3
Set the cameras far clipping plane to 28
In render globals set:
- File Name Prefix: zDepthTest
- check the "Depth Channel(Z Depth)"
- change the camera from persp to camera1
- Resolution Preset: 640x480
- Anti-aliasing Quality Preset: Production
Batch render the frame

The Photoshop approach (not very good imho. if someone knows a better way i'd like to hear)
-------------------------------------------
open the zDepthTest.iff in photoshop (hopefully you got the maya iff plugin for photoshop. it's free but i can't remember where i found it). in photoshop select Window->Channels. you should see channels RGB, Red, Green, Blue, Alpha 1 and Alpha 2. Alpha 2 is the z-depth channel. click on it and zoom in to one of the spheres edges. it's all jagged and aliased. Do a gaussian blur with a radius of 1,0. Much better. Now zoom out to 100%. Control-click the Alpha 2 channel. The selection marquee looks a bit weird but let's ignore it. Choose Select->Inverse. Click on the RGB channel. Now start blurring with the selection still active and you should see the DOF like effect showing up.

The After Effects approach
-------------------------------------------
AE can read Maya IFF files but it can't (afaik) access the Alpha 2 channel (the z-depth info). Render the scene to an RLA file which is more suitable. Import the zDepthTest.rla in to AE and make a composition of it. Now apply an Effect->3D Channel->Depth Of Field. Nothing happens until you start tweaking the settings. For example:
- Focal Plane: 0,2 (this is the focus distance. keep withing 0 - 1. 0 = far, 1 = near)
- Maximum Radius: 5 (this is the max blurriness)
- Focal Plane Thickness: 0,1 (like focus region scale in maya. keep within 0-1)
Now you should have the furthest sphere in focus while the other is blurred. Change the focal plane to 0,7 and the foremost sphere should be somewhat in focus.

There you have it... I hope user added image


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# 15 21-10-2003 , 07:24 PM
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HAHAHAHHA I GOT IT.......


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And after calming me down with some orange slices and some fetal spooning,
E.T. revealed to me his singular purpose.

--TOOL, 10,000 Days---

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