Author Topic: Stuck on Calculating Displacement  (Read 1643 times)

2022-09-16, 18:18:19

BigAl3D

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So I've worked with this scene before. I even posted about the best way to get a rug texture into a PBR material. Now using Substance Sample which does a pretty nice job. Anyway, I was even able to use the Interactive Viewport with enough speed that it was usable. Yesterday, I downloaded several furniture assets from Cosmos and added to this scene so I could do a quick render with good lighting to show someone. It seems to get stuck on Displacement now. I've let it go for overnight (12 hours) with no success. I then deleted all the proxies of the new models and romoved their materials. Same thing. Stuck on Calculating Displacement. I quit any app that uses a lot of RAM. Rebooted for a fresh start. Same thing. Downgraded from v9 Daily to v8 Hotfix 1. Same problem. Tried two versions of C4D. No luck.

I can easily go back to the original scene so it's not the end of the world. I'm just looking for advice on troubleshooting this problem for any future project that I can't afford to start over.

iMac Pro, 128 GB RAM
OS Montery 12.5.1

2022-09-16, 21:53:47
Reply #1

burnin

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Check Render settings > Performance Settings > Displacement> Screen Size (px): 2 <<< go ^ XXL, to see where you're at. Then gradually lower, until you find your sweet spot.

--------------------
Q. for devs:
Is there a "String option" to globally disable Displacement (switch it on/off)?

2022-09-16, 23:12:27
Reply #2

BigAl3D

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Looks like it's at the default of 2. OK, so after changing this to 8 and trying again, I got a new error. Something about the Scene Bounding Box Being Too Large. So I checked the scene scale. All good. Then I selected all objects and hit the letter O. This will zoom the view to include all objects in your current selection. Curiously, everything disappeared. Long story short, I repeated this process, but only selecting one group of objects at a time. Everything worked until I hit one object, the Main Walls, then everything disappeared again. Progress. I had modified this object the other day. So I selected all the point and hit Optimize. Now when I hit O, boom. Back to normal and I can see the objects again.

Now it renders again! Yahoo! Your tip got me in the right direction.

Now I need to learn more about the pixel size setting and, aside from RAM usage, why I would need to adjust it. Would it render faster? I know there is probably a loss of detail at some point.

2022-09-17, 03:54:39
Reply #3

burnin

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I assume your "runaway point" made bounding box "too large" (out of bounds for safe computing) and too small of a displacement value made machine too compute that long & far... it's unable to think "OoB" :) in this regard it's worth knowing about FPP - float-point precision, which defines hard limits for "virtual" worlds, and brings lots of incomprehensible issues for hairless apes, which is even more cumbersome handling it on GPUs (half size;) so "View Clipping", "nanites" & ultra fast EEC memory units are coming to rescue... in short, render-time micro-poly adaptive displacement is similar stuff in "off-line" rendering with more virtual space/numbers to  maneuver, also more complex thus slower, yet more precise still and relative. In both, user can define "View Clipping".

Hope you can sum it up and extract some to further find directions in this meandering matrix...

« Last Edit: 2022-09-17, 03:58:21 by burnin »