Author Topic: uvw randomizer changes every time with new render  (Read 5226 times)

2020-03-06, 09:10:05

albertoiuav

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Hi guys,

i have quite a big problem with uvw randomizer and Cinema 4d.
I created a tiles floor and using uvw randomizer and multishader to have great variation on it.

The problem is that everytime i press render, the randomization changes.
The customer asked me to have the tiles "as the 1st draft", but if everytime it changes, would be quite impossible.
I use uvw randomizer lot of time so, is a big issue for me.

Maybe i set something wrong with parameters? I attached them also with 3 render tests.
Hope that someone could help me.

thank you

2020-03-06, 15:06:10
Reply #1

aler

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This is probably a disease of the Cinema.
The first time I noticed this with VRay (randomization with Output Wrapper). In Corona 5 appeared Multi Shader and the problem is exactly the same. But I traced the reason: randomness changes if you add / remove or show / hide objects in the scene.

2020-03-06, 15:07:37
Reply #2

TomG

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How are the objects being created? Are they instances (and if so, what is creating those instances?), or physically unique regular objects?
Tom Grimes | chaos-corona.com
Product Manager | contact us

2020-03-06, 15:13:11
Reply #3

albertoiuav

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This is probably a disease of the Cinema.
The first time I noticed this with VRay (randomization with Output Wrapper). In Corona 5 appeared Multi Shader and the problem is exactly the same. But I traced the reason: randomness changes if you add / remove or show / hide objects in the scene.

Oh, this is quite a big problem.
To be honest i didn't noticed it when i used Vray in the past.

2020-03-06, 15:15:05
Reply #4

albertoiuav

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How are the objects being created? Are they instances (and if so, what is creating those instances?), or physically unique regular objects?

Objects are simple cubes scattered with Mograph as "render instances".
And inside Multi shader settings i used "object" as Mode.

Do you think is a fixable bug?
Thank you

2020-03-06, 17:52:36
Reply #5

Cinemike

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Do the changes literally happen every time you render, no matter what, or did you apply other changes to the scene, like adding/removing objects and/or changing the order of objects in the object manager?

2020-03-06, 18:18:59
Reply #6

TomG

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Hi! This one is a known issue, relating to the IDs that Mograph tags onto the objects - unfortunately, while we know about it, the fix is non-trivial, which is why we don't have any estimate for when we might have a fix for it. In most cases it doesn't change like this, but it can happen unfortunately (as you've found) - some thoughts as workarounds in the meantime, if you disable render instances, it should be less of an issue.

If you need to reference the issue outside this forum thread, you can give us this ID number for the issue (Internal ID=361586625) - and we've made a note in that internal tracker to come post here when a fix is available for testing (but as I mentioned, no expected or estimated date for that yet, sorry)
Tom Grimes | chaos-corona.com
Product Manager | contact us

2020-03-06, 18:40:01
Reply #7

ECBworks

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Do the changes literally happen every time you render, no matter what, or did you apply other changes to the scene, like adding/removing objects and/or changing the order of objects in the object manager?

Hi, I recently posted the same problem. You can bypass this problem by always putting the object affected by uvw randomizer that you want in top of the object manager, the object below it wont affect it. Not a perfect solution but at least there's not too much change to do in my animation.

2020-03-06, 18:56:43
Reply #8

Cinemike

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@albertoiuav
If you have it in your C4D version, try using the Variation shader. Put the material tag on the object, not the cloner, and use the mode "Object Name" instead of "Objects".
You can also use several different textures plus the UV randomization with the Variation shader and it should be a stable solution.

Let me know if it works for you :)
Michael

2020-03-06, 20:00:56
Reply #9

Designerman77

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Do the changes literally happen every time you render, no matter what, or did you apply other changes to the scene, like adding/removing objects and/or changing the order of objects in the object manager?

Hi, I recently posted the same problem. You can bypass this problem by always putting the object affected by uvw randomizer that you want in top of the object manager, the object below it wont affect it. Not a perfect solution but at least there's not too much change to do in my animation.


Okay, interesting. Gonna try this.

However, the UV pattern changes also if your objects are NOT Mograph-objects... can be trivial stuff.

Yep... reported this problem about half a year ago...



2020-03-10, 21:52:39
Reply #10

tshelton

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Just an idea, have you tried using "Object buffer ID" for the mode of the multi shader, then add a compositing tag to every object that has the material applied. Then in the compositing tag, select the "Object Buffer" tag and enable the first one, make it a 1. Then go onto every other object's compositing tag and do the same but increase the number by 1 each time, or just do a mix of 1, 2, or 3, depending on how many variations you want. It is a little lame because you have to go through and manually set it up the first time, but then everything is still all within one material, and you can modify which variant is applied to which tile by changing the object buffer ID. I've only used this once for lighting an LED tube so I could control each LED within the material, but I haven't put it through much testing, so it'll be interesting to see if it works.

EDIT: So I misread the original post, and assumed you were using the multi shader, not the UVW randomizer, so you could test the randomizer, but I don't know if it would work the same. But you could accomplish what you are doing with the multi shader instead I would think. (You would just create a different texture, or send your texture through a layer node and add a transform to manually transform your texture, and make a few variations then plug them all into the multi shader)
« Last Edit: 2020-03-10, 21:56:46 by tshelton »

2020-03-11, 01:32:56
Reply #11

Designerman77

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Just an idea, have you tried using "Object buffer ID" for the mode of the multi shader, then add a compositing tag to every object that has the material applied. Then in the compositing tag, select the "Object Buffer" tag and enable the first one, make it a 1. Then go onto every other object's compositing tag and do the same but increase the number by 1 each time, or just do a mix of 1, 2, or 3, depending on how many variations you want. It is a little lame because you have to go through and manually set it up the first time, but then everything is still all within one material, and you can modify which variant is applied to which tile by changing the object buffer ID. I've only used this once for lighting an LED tube so I could control each LED within the material, but I haven't put it through much testing, so it'll be interesting to see if it works.

EDIT: So I misread the original post, and assumed you were using the multi shader, not the UVW randomizer, so you could test the randomizer, but I don't know if it would work the same. But you could accomplish what you are doing with the multi shader instead I would think. (You would just create a different texture, or send your texture through a layer node and add a transform to manually transform your texture, and make a few variations then plug them all into the multi shader)


Thanks for the idea. Sounds super time consuming. Not an option when you have to do (for example) ten complete flats with all the interiors in a relatively short time.
We need stuff like this to simply work since we do our jobs for a living... not for playing around with the software.





2020-09-01, 19:25:57
Reply #12

jojorender

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This is still happening in the new V6.
UVW randomizer is promoted in the "major feature" section, but a known problem is not fixed... yet??
Maybe in the meantime you can put a note about the workaround, "ECBworks" posted, inside the shader.
This would have saved me a lot of tears and pulled out hair....