Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: kirmoos on 2015-11-06, 21:25:09

Title: Artifacts when rendering Displacement
Post by: kirmoos on 2015-11-06, 21:25:09
Artefacts appear in the form of steps using the corona-bitmap in the displacement slot in the material editor. How to fix it?

Corona 1.3 version

Title: Re: Artifacts when rendering Displacement
Post by: romullus on 2015-11-06, 21:56:14
Have you disabled filtering in CoronaBitmap?
Title: Re: Artifacts when rendering Displacement
Post by: kirmoos on 2015-11-06, 22:04:39
Quote
Have you disabled filtering in CoronaBitmap?
I tried filtering blur from 1 to 100, the result is the same. Interpolation - bicubic.
Title: Re: Artifacts when rendering Displacement
Post by: romullus on 2015-11-06, 22:48:00
What is file format and bit depth of your displacement map? Can you add turbosmooth and displace modifiers on top of that object and plug displacement map via Bitmap and CoronaBitmap to see if difference remains in viewport too?
Title: Re: Artifacts when rendering Displacement
Post by: kirmoos on 2015-11-07, 11:18:34
What is file format and bit depth of your displacement map? Can you add turbosmooth and displace modifiers on top of that object and plug displacement map via Bitmap and CoronaBitmap to see if difference remains in viewport too?

The format of the image .tiff (16 bit)

With applying the modifier Turbosmooth and CoronaDisplacemntMod nothing changes.
Title: Re: Artifacts when rendering Displacement
Post by: hubrobin on 2015-11-07, 11:25:11
Hey kirmoos,

can I have the scene or at least the bitmap? I will have a look at it and see what's going on.

Thanks,
Robin
Title: Re: Artifacts when rendering Displacement
Post by: romullus on 2015-11-07, 19:20:28
Robin, i was able to replicate that. Preparing sample scene now, will upload it on mantis.
Title: Re: Artifacts when rendering Displacement
Post by: kirmoos on 2015-11-07, 20:55:59
can I have the scene or at least the bitmap? I will have a look at it and see what's going on.

Here, I made the scene (ignore the missing textures). I tried to transfer this same piece in a new scene and render the artifacts disappeared. But after a while, the artifacts reappeared. In addition, the Displacement texture is not displayed correctly when changing its mode in the interactive render.
Title: Re: Artifacts when rendering Displacement
Post by: maru on 2015-11-10, 15:48:38
I think this is caused by the texture. As mentioned before, it is too shallow. You can even see the banding with your eye on the monitor. I don't know how you made the texture, but you could try generating it again with more depth (higher range between white and black).
Title: Re: Artifacts when rendering Displacement
Post by: romullus on 2015-11-10, 16:01:50
8 bit textures renders fine. 16 bit textures shows these steps and only with CoronaBitmap, so it's unlikely that this is problem with texture quality.
Title: Re: Artifacts when rendering Displacement
Post by: maru on 2015-11-10, 16:20:06
oh... ok.