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 05-01-2004 , 09:18 PM
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Particles not appearing in Batch Render

The particles in my scene are not Batch Rendering properly and I've done quite a bit of troubleshooting so far (but have not figured out what's wrong). Here's where I'm at:

I've got about 5000 particles in a scene. When I render a single frame from within Maya, everything looks great. When I Batch Render, the particles only show up in about 6 or 7 of 5000 frames! In the frames where they appear, they look correct.

What could be causing this?

My particle disk cache is good, because I can scrub back and forth in the timeline and the particles all behave themselves. I've rebuilt the particle cache several times, just in case, and am no closer to a solution.

I can tell that the correct camera is being used because both the camera and the emitter object are on motion paths and everything is tracking properly.

The particles are "cloud" type and everything I've seen indicates that they are to be s/w-rendered, which is what I'm doing.

I am especially confused because the particles show up correctly in those few frames (scattered randomly throughout the animation sequence) but are missing in all of the rest of the frames...

user added image
Please Help!

# 2 05-01-2004 , 09:38 PM
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Do you have a particle shader attached to the particles?

# 3 05-01-2004 , 09:39 PM
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Yes -- particle cloud shader.

And like I said, everything looks GREAT when I render out single frames or when the Batch Render "accidentally" gets one right.

Very frustrating...

# 4 05-01-2004 , 09:55 PM
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I think you are misunderstanding what I mean. See... there is a particle TYPE which you stated you had set to cloud. This is completely different from a particle SHADER. If you open hypershade, you will see that you can create particle shaders. This is what you need to attach to your particles. You right-click the shader in hypershade with your particles selected and choose "attach to selection."

I really hope this is the solution. user added image

# 5 05-01-2004 , 10:01 PM
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The Attribute Editor for my shader is listing it as "particleCloud": ExhaustVT.

The particleCloud2SG node is listing ExhaustVT as the Volume Material.

Within the particleShape1 node, I have Particle Render Type set to "Cloud (s/w)".

???

# 6 08-01-2004 , 11:04 AM
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I've had this problem before as well, mine would randomly dissapear in batch rendered sequences. I can't remember if and how i fixed it as I think it was before I upgraded my computer. I think it may have been a memory issue, does the output log give any errors? or there is a render analyse tool I think that might show you where the problem is. Is your machine up to spec in terms of memory?

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# 7 08-01-2004 , 05:12 PM
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I'm getting no errors in the output log and have 2GB of RAM.

I tried the render again yesterday and it didn't include particles until frame 128. At frame 128 they were perfect -- in the right places and everything.

They disappeared after frame 168, never to be seen again...

I hate this I hate this I hate this.

I'd scrap the whole thing, since I'm just experimenting with motion paths, but it really annoys me that I can't figure out what's wrong.

user added image

# 8 08-01-2004 , 05:28 PM
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to be honest I would scrap it. I remember when I had this now! it was right before xmas and it happened when I added a per particle attribute to something i shouldnt (i think) and then it was doing exactly what you are saying. So i just scrapped it and started again.

It's not fun i know but it would probably be easier in the long run. Just make sure you save often so you can backtrack if necessary user added image

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# 9 08-01-2004 , 05:36 PM
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Thanks. Not the answer I was looking for, of course, but at least one that has some basis in experience.

I appreciate the help.

On to bigger and better things!!!:bgreen:

# 10 08-01-2004 , 05:53 PM
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just one of those things I think, I had never seen it before and I've never seen it since (touch wood)


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# 11 09-01-2004 , 04:55 AM
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First, if you were to select ALL of your objects and EXPORT ALL or SELECTED (try both) to a completely NEW file, then re-setup your render globals, does that help?

Also, in your render globals, is your "renderable camera" correct?
Or is it set to the default "perspective"?


Israel "Izzy" Long
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# 12 09-01-2004 , 02:43 PM
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I have not tried the export idea yet. Sounds like an interesting idea, though.

As far as the camera goes, I am sure I've got it set up right in the Render Globals because the camera is on a motion path and I see that in the render output.

# 13 09-01-2004 , 06:22 PM
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I would also suggest creating a particle disk cache. This could help.

# 14 09-01-2004 , 06:45 PM
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set the state of particles from frame 128 (or when they decide to render) to the begining frame.
this may alter your end results (or begining result)

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