Chaos Corona Forum
Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: VizRepublic on 2020-07-01, 20:18:28
-
Hello,
I seem to be getting this tessellation issue lately when using displacement on certain surfaces. It's subtle in the Lightmix pass but very apparent in the Ambient Occlusion pass which becomes unusable like this. Its generally appears when its on an extruded spline that this issues happens. I have tried to fix it by adding more geometry to the object by either subdividing or tessellating it but neither worked, just made it worse in fact.
Anyway to solve it? any help would be appreciated.
Thanks.
-
Which Corona and displacement version + size is this? I repeatedly have issues with such "draft" geometry as well (even with less obvious problematic topology than in your case). In many projects you need all flexibility you can get, so something like booleans or extruded splines - to maintain the full stack, which usually leads to geometry that displacement simply cannot handle reasonably currently.
Unfortunately not-so-new-anymore 2.5d displacement is very very sensitive to edges and even not-so prolonged edges and sometimes I still feel like being in emperor's new cloth when it comes to Corona 2.5d displacement. A few quick options however:
- retopo the wall to proper quads or at least to a somewhat controlled subdivision with equilateral triangles at best
- subdivide like crazy (10 to 5 cm) using a subdivide modifier on top
Rapid workflow for walls like this that works somewhat ok for me would be:
- create wall, untick "edges only" in object properties to see what's happening
- do a basic retrianglulation if needed
- subdivide result (subdivide modifier) using a moderate value of about 0.5m
- do vertex paints at this stage if needed e.g. for blending materials/maps later
- model openings (extruded splines will do perfectly, flexibility here as well)
- create a proboolean out of the wall and substract the openings, set it to "Manually" in "Advanced Options" to prevent yourself from jumping out of the window sooner or later. Also set "Planar Edge Removal" to "No Edge Removal"
- if you need different material IDs later, make sure the operand has the right ones, put a material modifier on top before substracting it
- then add things like UVW map modifier, Noise or whatever is needed also as modifier or even add another subdivide modifier, smaller that the first one (e.g. 10cm)
This way you have a vital modifier stack where changes can still be done instead of having collapsed geometry which may works for displacement/AO but is baked. Screenshots: left is subdivision, right is bump with 10x10cm checker, beauty and AO. Doing the subdivision on the wall before creating the boolean out of it results in something suitable for displacement here.
Good Luck
-
Is it any better if you switch from the 2.5D displacement to the classic one? (uncheck the "New 2.5D displacement" checkbox in the Performance tab)
We have some similar issues logged internally, so once they are fixed, this one should be re-tested too.
(Internal ID=420575272)
-
Thanks for the help. I will definitely try out those methods, hopefully they do the trick!
-
Hi,
We have greatly improved the 2.5d displacement tessellation in the latest v7 daily build.
It should remove a great deal of the artifacts which were caused by the 2.5d displacement. You can find a build here: https://forum.corona-renderer.com/index.php?topic=30876.msg182287#msg182287
I will look forward to your feedback.
Cheers,
Rowan
-
we personaly dislike the 2.5 displacment method, and keep using the "real" one. We use the corona displacement modifier to choose the detail level of the objects in view. Also redrawing the geometry with "subdivide" and such tools with relax values seem to help in these cases...
-
we personaly dislike the 2.5 displacment method, and keep using the "real" one. We use the corona displacement modifier to choose the detail level of the objects in view. Also redrawing the geometry with "subdivide" and such tools with relax values seem to help in these cases...
You won't have an option in the next release 2.5 or nothing. Although the recent developments look promising, still not a great idea to completely remove the old one imo purely for legacy purposes. Unless of course they can guarantee that the 2.5D will look the same as the old displacement in my older scenes.
-
+1.. look at the mask option the removed from the material shader option... it's a shitshow atm for us.. we need to double render in animations, a damn nightmare and costing us alot of money