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rlguy / Blender-FLIP-Fluids

The FLIP Fluids addon is a tool that helps you set up, run, and render high quality liquid fluid effects all within Blender, the free and open source 3D creation suite.
https://www.blendermarket.com/products/flipfluids
GNU General Public License v3.0
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Fluid Artifacts near domain surfaces/floor creating bumps in the fluid mesh #572

Open gluttonium opened 2 years ago

gluttonium commented 2 years ago

Hello FlipFluids developers,

I noticed some minor visual bugs in my simulations and haven't really found a good way to avoit it. The fluid mesh generates some weird carvings/bumps near the domain floor and sometimes on the domain walls giving the fluid mesh in my final renders a weird result. As result there are some weird out of place reflections/refractions on the fluid facing the scene's floor because of these weird bumps in the mesh. (I usually use the FF volumetric ocean material or own materials with glass and volume...) Even when the simulations is not chaotic and there isn't much movement in the water the bug still occurs and the mesh starts to generate these sometimes noisy and annoying bumps on the floor and sides.

I tried increasing the fluid particle scale which lead to a little less bums but it created very blobbly and big fluid splashes. Increasing the simulation resolution makes the bumps more detailed but doesn't really get rid of it... I went up to 250 (my PC can't handle more) and still didn't get rid of the bumps.

Would be cool if there is a better method to avoid this visual bugs or maybe a patch in future updates.

Sincerely, Gluttonium

System Information

Blender Version: 3.0.0, master, 2021-12-02 18:35, f1cca3055776 Addon Version: A FLIP Fluid Simulation Tool for Blender (v1.2.1 Stable 03-DEC-2021) OS: Windows-10-10.0.19044-SP0 GPU: NVIDIA GeForce GTX 1050 2GB/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 511.79 CPU: Intel(R) Core(TM) i5-8400 CPU 6 cores @ 2.80GHz RAM: (1(2) KINGSTON ValueRam KVR26N19S6 8 GB DDR4 2666MHz (not pre-installed, ordered+installed Dec. 2021) (2/2) 8GB DDR4 2666MHz ECC Unbuffered DIMM CL19 1Rx8 1.2V (looks pretty much like the one that's pre-installed, from 2018)

Attachments (pictures taken from below the mesh)

grafik

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grafik

https://user-images.githubusercontent.com/98273272/155844426-9e83e568-1086-4126-bafb-caef46c50f31.mp4

rlguy commented 2 years ago

Hi Gluttonium,

These type of artifacts are caused by a side-effect of how the simulator works. The liquid simulation is tracked by particles and the mesh is generated from these particles. Within the simulator, particles can separate and create gaps which may not be filled in by the mesh generation process. This can become more apparent in splashier and chaotic simulations, or simulations what a lot of swirling motion.

I'll mark this as a known issue and perhaps a solution to reduce or eliminate these artifacts could be found in future development.

- Ryan