Displacement Hell House Vol 4

# 1 11-10-2015 , 06:52 PM

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Hi all

I am having a completed nightmare with the displacement maps i generated for the house for some strange reason the edge roof tiles are floating in the air. I have validated that the patch in Mari is black with no textures i have tried changing it to transparent, grey, darker grey but nothing seems to work. One thing i notice when i went into Mari to verify everything was that i had the displacement channel assigned to the bump in the shader. I changed this and assigned the bump to the bump and the displacement to the displacement. I noticed in the view-port that part of the roof was sticking through the tiles (the ones i am having problems with) so i reduced the displacement Bios so it looked OK in Mari

I then exported the channel and did a fresh render and its still the same. really not sure what i am doing wrong here.

Any thoughts?

cheers Myth

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# 2 11-10-2015 , 07:18 PM

SM Tea Boy
Join Date: Apr 2002

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I'll record a short video now take me about half an hour, displacement can be a PITA so it's easier for me to record a short vid

BRB
David user added image

From a readers' Q and A column in TV GUIDE: "If we get involved in a nuclear war, would the electromagnetic pulses from exploding bombs damage my videotapes?"

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# 3 11-10-2015 , 08:02 PM

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many thanks Dave, much appreciated user added image

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# 4 11-10-2015 , 08:19 PM

SM Tea Boy
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In a nutshell the patches in mari with no displacement should be 50% grey. The displacement textures alpha gain should be set to 1 and critically it's alpha offset should be set to -0.5

This will set 50% grey to zero displacement, black to negative displacement and white to plus displacement.

There should also be a mental ray displacement approx node on the roof geo.

Glad to see you sticking with this project, it's a massive undertaking hopefully you'll learn a lot, but it's not easy!

The video will give more information, hopefully this sorts the problem for you if not let me know. It also might be a bit basic but i thought the extra information might help other people out.

https://www.youtube.com/watch?v=wmrWtWpOKV8

From a readers' Q and A column in TV GUIDE: "If we get involved in a nuclear war, would the electromagnetic pulses from exploding bombs damage my videotapes?"

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# 5 11-10-2015 , 08:28 PM

SM Tea Boy
Join Date: Apr 2002

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Video should now be online, btw what you set the displacement setting to on the shader in Maya will have no effect on what you see in Maya this is just to help you visualize the displacement in Mari.

If this does not solve your problem export just the house and roof geo and the displacement map from Mari and i'll do a proper breakdown of it for you.

All the best
David

From a readers' Q and A column in TV GUIDE: "If we get involved in a nuclear war, would the electromagnetic pulses from exploding bombs damage my videotapes?"

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# 6 11-10-2015 , 08:52 PM

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many many thanks Dave, i will give that a go. I have tried grey previously but will give it a go and validate it again.

Many thanks

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# 7 12-10-2015 , 11:18 AM

SM Tea Boy
Join Date: Apr 2002

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Let me know if you managed to get it fixed. If not i'm standing by to work out why user added image

David

From a readers' Q and A column in TV GUIDE: "If we get involved in a nuclear war, would the electromagnetic pulses from exploding bombs damage my videotapes?"

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# 8 12-10-2015 , 12:26 PM

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Hi Dave,

I made sure all the patches in Mari were 50% grey for everything on the displacement layer other than the Chimney and the roof.

This result seems to be the same. user added image

Are you running the latest SP from Autodesk Dave? because thats the only thing i can think of to be honest. I will, when i get home tonight, upload the displacement textures and the scene file to you and hopefully you will work your magic and say "you have done this, tut tut user added image

)

Many thanks for the additional assistance with this Dave, much appreciated.

Cheers Myth

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# 9 12-10-2015 , 01:14 PM

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I'm running the latest service pack so it can't be that, the fact your tiles are splitting apart like that means there is probably something wrong with the displacement offset. Which makes me think you may not have the displacement image colour management set to raw?

Make sure your displacement image is set to raw and not sRGB.

Displacement can be tricky, if you've not worked with it much it's difficult to diagnose the problems.

Things to check:
Displacement image set to raw, the alpha gain to 1 and the alpha offset to -0.5 open the image in PS to confirm the grey is 50% gray rgb 128,128,128.

If none of that works for you send me the file and textures and i'll let you know where you have gone wrong user added image

All the best
Dave

From a readers' Q and A column in TV GUIDE: "If we get involved in a nuclear war, would the electromagnetic pulses from exploding bombs damage my videotapes?"

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# 10 13-10-2015 , 05:21 AM

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Hi Dave,

After some playing about last night i switched to use your displacement maps as i just wanted to see if it was Maya or my maps from Mari. Yours worked perfectly. Checking Mari again for some reason when i export all patches on the displacement channel the first map comes in as a grey dot within a white background. No matter what i do I am not able to get this to export correctly (or is this correct?).

You really have to be careful in Mari when blending layers and exporting them which i now realise. One thing i would like to ask is if i make a mistake on a patch and have baked the texture, how do i erase that without filling the patch or applying a mask? say in an earlier say or at some point throughout the process so CTRL + Z wouldn't work

This is a mammoth task, the amount of work that goes into the final render is huge but IMPO it is definitely worth it as your results speak from themselves. I think this is the best project i have ever worked on.

Many thanks

Last edited by mythandra; 13-10-2015 at 08:31 AM.

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# 11 13-10-2015 , 10:14 AM

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Your first patch should definitely not be saving out as a dot! are you using the export all? If you go into your mari projects tab you can archive the scene and send it to me, i'll then be able to tell you why user added image

If you have made a mistake you will need to mask it out. However the mask can then be baked onto the layer. When it comes to mari and masking there is a bit of a learning curve. You should get into the habit of breaking everything up into separate layers that way a mistake won't cost you the entire texture.

Also don't worry about the small mistakes for now, you'd be amazed at what you can do with render passes and post production. Getting the image out of Maya and into Nuke or other composing app can let you get a grasp on what needs fixing and what does not. It will also make a huge difference to how your image looks.

If you want to jump ahead a bit and see what's possible in Nuke (you can now get nuke studio free) I'll be happy to send you my nuke file and final render so you can have a look.

I tried to cover a full pipeline in this tutorial because IMO if you don't understand the full process of what goes into to a final image you'll never know where the work needs to be put in to make an image better. You'll then end up endlessly rendering images in Maya trying to get a look that would have been much more achievable in another part of the pipeline.

Everything you are trying to do right now is difficult, stick with it and try not to throw the PC out the window user added image

i've come close more than once myself.

All the best
Dave

From a readers' Q and A column in TV GUIDE: "If we get involved in a nuclear war, would the electromagnetic pulses from exploding bombs damage my videotapes?"

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# 12 13-10-2015 , 10:32 AM

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many thanks Dave, I have Nuke installed in preparation for this project, haven't launched it yet though user added image

I am just archiving the project now and will IM you a link if that's OK.

Thanks Myth

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# 13 13-10-2015 , 10:38 AM

SM Tea Boy
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No problem user added image

From a readers' Q and A column in TV GUIDE: "If we get involved in a nuclear war, would the electromagnetic pulses from exploding bombs damage my videotapes?"

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# 14 13-10-2015 , 01:09 PM

SM Tea Boy
Join Date: Apr 2002

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Problem solved! In a nutshell:

First problem with the grey dot was a simple mistake of exporting selected patches and not all patches easy mistake to make!

Second problem, because of the adjustment stack on the displacement layer you were never exporting a 50% grey image, took me a while in the video to notice, another easy mistake to make.

Watch the video user added image

I get a render out that works just fine with your displacement. Small colour error in displacement equals a large headache at render time!

https://www.youtube.com/watch?v=HrI68u-n9QM

All the best
Dave

From a readers' Q and A column in TV GUIDE: "If we get involved in a nuclear war, would the electromagnetic pulses from exploding bombs damage my videotapes?"

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