Jagged Displacement Issue - Roof Sheeting

[Morne]

Hi all

Another one of those...
The subdivide is set to 250 and the UV is plane map 200mm x 200mm
How can I resolve this issue?

This is a crop of a 4K image:


And here's the settings:


I tried with and without filtering, doesnt make much of a difference. Also with and without the subdivide

[Raven]

Hi Morne

2 questions
What filtering is the bitmap using?
And what bit depth is the map?

Had similar issues recently, can't remember exactly what I did to fix it, but it was definitely related to those 2 things.

Any reason this isn't just modeled, to me it would be easier to control and render faster?

[Morne]

It's all in the attachements from my 1st post. Its a gradient ramp and like I said, with or without give same result. I also recreated the map in photoshop, still same result. (the photoshop file is 8 bit)

HOWEVER
If I use a different map the give the sheeting a wave profile instead of the step profile, then it works great.
But that doesnt help me now as I need it with the step profile...

Will try the photoshop file in 16bit and see...

[Raven]

Sorry missed the settings. It is the edge length. On something like this you'll need 2 or 1.
Here is a quick scene I threw together.

Gradient should be fine then.

[Morne]

It's always just one stupid little setting somewhere!
Thanks Raven

2 was better, but 1 solved it!

I must just say it renders much longer now, but at least it looks good!

[Dariusz Makowski (Dadal)]

Would not a 2d displacement be a much better option for this? It should render faster than 3d and produce good results...

[Morne]

I also have the same thing on a "box", not just the roof, will 2D still work?

[Dariusz Makowski (Dadal)]

Yea 2d should work on anything... flat/curve/box/etc etc. Just try it. U might need to crank up 2d resolution and precision. I got good results with that.

[Morne]

Yes 2D appears to be working great in this case, with the default of 512 res and 8 precision

Just my GI is giving some splotches between the narrow parts where the roof steps up in the displacement. I have LC 2000 subs, IRmap in medium preset and increased int sampls from 20 to 40

[Dariusz Makowski (Dadal)]

Set samples to 160 and the number interpolation to 140. It will be very smooth and lovely

[Morne]

Set samples to 160 and the number interpolation to 140. It will be very smooth and lovely

What samples to 160?

You mean HSph subdivs to 160 and interp sample to 140?
I've got those on 50 and 40 currently

[Dariusz Makowski (Dadal)]

Yup thats what I mean. I usually run at 150/150. Its the minimum setting I find to get very good smooth GI. Then only min and max rate to control accuracy of it. Sometimes I lower interp to get bit more sharpness but I risk blotches.

[LarsSonparsson]

Just a side note

The "Max subdivs" in displacement doesn't affect anything when using 2d or 3d displacement. It's counts only when using displacement in subdivision mode.

[Dariusz Makowski (Dadal)]

Heya

You know I sort off agree with you but when I use 3d displacement. I if I have max subdiv set to 1 and set to 30 I see big difference so I'm lost!

[LarsSonparsson]

Just made a quick test. See the attachment.

Same plane (3x3) using A: 3D disp. with 1 subd, B: 3D disp. with 20 subd and C: subdivision displacement with 1 subd. First two gives exactly the same results.