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?
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…
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.
Roof Panel.zip (45.2 KB)
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!
Would not a 2d displacement be a much better option for this? It should render faster than 3d and produce good results…
I also have the same thing on a “box”, not just the roof, will 2D still work?
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.
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
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
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.
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.
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!
The subdiv is the same thins as you apply turbo smooth + displace and texture in to it. It has different algorithms to deal with subdivision as well as its a lot faster to manage from memory point of view. Basically lets say (imaginative numbers) a car has 100k polygons, TS 1 = 400k polygons, TS 2 = 1.6 mil polygons TS 3 = 6.4 mil polygons.
Now if you use displacement in subdivision mode is exactly the same case Disp_subD 1 = 400k polygons/ Disp_subD 2 = 1.6mil polygons / Disp_subD 3 = 6.4mil polygons. Now they all will look pretty much exactly the same. The only difference is that TS 3 will eat up 4gb(not actual number) of ram and Disp_subD 3 will yeat 200mb ram. Displacement is being loaded and generated dynamically at render bucked level. Where as TS has to be pre-calculated.
I agree about everything. Yep, that’s the way how subdivision displacement works. …or should we call it subdivision surfaces?
But I was just trying to show my point about the 3D displacement. So that the “Max Subdivs” number doesn’t have any effect to it. Only edge length matters.
Somehow that is a common mistake people are making. Trying to adjust “Max Subdivs” to get better or faster displacement.
I think that the whole “Max subdivs” should be greyed out when 2D or 3D mode is selected, so it wont confuse people.
Yes, you are right, we should probably do that.
Best regards,
Vlado
Thanks all…
Any ideas on this now: I’m getting lots of gi blotches on the displaced sheeting, but everywhere else it is smooth. I eventually went with 2D displacement. Juts the gi blotches giving me issues now.
My irmap settings are medium preset with HSP sub on 120 and inter samples on 40
also tried 160 and 140 and also tried 50 and 40, doesnt seem to make a difference.
LC is default but with 2000 subs, use lc for glossy ticked, retrace ticked on 0.5 and also pre-filter on 20
