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Displacement+Normal Map bug
Posted: Wed Oct 29, 2014 11:21 pm
by grain
Hi there, apologies if this has already been resolved somewhere.
I'm half way through my first commercial job using octane render and it's all fine except for a strange bug I'm encountering when using normal and displacement maps on the same material.
When using both simultaneously there is a weird diagonal line between each face (basically splitting quads into tris) and the normal map gets inverted on one half of the quad. It's quite a bizarre effect, I hardly noticed it at first as I'm using a very subtle paper texture in my normal map so it wasn't hugely visible.
I found someone talking about the same issue on the lightwave forum but didn't find it here - are there any fixes or workarounds for it?
Cheers.
Re: Displacement+Normal Map bug
Posted: Wed Oct 29, 2014 11:24 pm
by glimpse
short answer - You can use both of them, should stick with one. I'd advise simply combine those two & use one higher resolution texture.
Re: Displacement+Normal Map bug
Posted: Wed Oct 29, 2014 11:50 pm
by grain
Thanks for the quick reply - I'll give it a shot when I'm at work tomorrow. I am using an 8192x8192 displacement map so not sure how much higher it needs to be.. hah.
Re: Displacement+Normal Map bug
Posted: Thu Oct 30, 2014 9:49 am
by atome451
Maybe an explanation: i've made a quick test with a noise inside the C4D effect > Normalizer and the result give this kind of curious triangles inverted normal map with a sphere but not with a cube. With a normal map bitmap, it works fine on both.
Not sure but maybe it'll help you.

- Normal channel with a bitmap

- Normal channel made with a noise inside the C4D effect normalizer
Re: Displacement+Normal Map bug
Posted: Sat Nov 01, 2014 11:24 am
by grain
Hi guys, thanks for the suggestions.
Ultimately combining the two maps together was the fix for this, I couldn't get both normals and displacement working together properly. I tried making everything octane imagemap textures, no c4d shaders, everything 16 bit, etc to no avail.
It would be great if the two could co exist as it would speed things up. I've attached a still of the issue I was having for reference. I've graded the one on the right and put rough wireframe over so you can see where the breaks in the normal map are occurring.
Re: Displacement+Normal Map bug
Posted: Sat Nov 01, 2014 11:35 am
by aoktar
there maybe some problems on displacement and bump/normal maps. you can check standalone topics for this kind of issues
Re: Displacement+Normal Map bug
Posted: Mon Nov 03, 2014 1:31 am
by FooZe
Yes, this is known limitation. Displacement cannot be used with normal or bump maps (or at least, if you do then you will get these artefacts).
Re: Displacement+Normal Map bug
Posted: Mon Nov 03, 2014 12:39 pm
by grain
Thanks for letting me know.
Does this also include displacement and shadows? I'm encountering a strange issue where I have an object sitting on a plane, I am displacing the plane around the object but not directly under it (ie displacement is black around the object so in theory no geometry movement) but it's lifting the mesh up even where it's black. I compensate by using the shift parameter but the shadow moves with the shift, so in other words the shadow looks like it's being cast by an object slightly lower than my actual visible one.
Weird.
Re: Displacement+Normal Map bug
Posted: Mon Nov 03, 2014 9:05 pm
by FooZe
I'm having a little trouble getting my head around what you are seeing. Are you able to post a screenshot or even better, a simple scene that shows the problem that we can reproduce here?
Re: Displacement+Normal Map bug
Posted: Tue Nov 18, 2014 5:55 pm
by grain
Well that job has finished up now, it was not too painful all up. The displacement + normals bug remained throughout however combining the maps into a single displacement map worked. A bit of a pain in the ass but not too bad.
The final job is at
http://www.toyota.com/fuelcell/index.html, it's the intro video that plays when you hit the page. It is compressed as hell, I will post a higher quality version when it goes online.
A couple of notes - the end shot with realistic car is created by a different company (not me) using vray. The clouds and train steam are Turbulence 4D. And that's about it.
Any questions I'm happy to answer them.