Solution to Distortions in Hair System during Batch Render in Maya
This is a common issue in Maya when using nHair / Hair System with balls or animated objects and performing a Batch Render. If the per-frame render looks good but the batch render is distorted, it's most likely that the hair simulation system is not being evaluated correctly in batch rendering. Fortunately, there are several solutions in Maya to fix this. Let's fix it! 🛠️
Save and Use Hair Cache (nCache)
One of the most effective solutions is to create a cache of the hair simulation:
- Create cache: Go to the FX menu > nCache > Create New Cache > nObject.
- Configure cache: Create a cache for the hair system (HairSystem) for the entire simulation.
- Freeze simulation: This freezes the simulation and ensures that Maya does not recalculate it during render.
- Enable cache: Then enable the use of the cache in the HairSystem node.
This ensures that the hair simulation remains consistent in every frame of the render. A reliable solution!
Enable Cache Evaluation in the HairSystem
Make sure that in the Attribute Editor of the hair node, the Use Cache option is enabled before launching the batch render. This guarantees that Maya uses the created cache and does not recalculate the simulation during rendering. A crucial step! 🔑
Avoid Real-Time Playback Before Rendering
If you do a preview and then Batch Render without restarting Maya, sometimes the simulation stays in memory with incorrect data. To avoid this, save your work, restart Maya, and launch the batch render directly. A quick restart can save you a lot of headaches! 🔄
Verify Hair Node Settings
Some older projects use deprecated hair settings. Make sure you are using the nHairSystemShape node with its core active. Also, verify that the render engine (like Arnold) is recognizing the hair. In some cases, you need to enable the HairSystem visibility attributes in the render. For Arnold, check in Render Settings > System > Hair / Fur. Leave nothing to chance! 🎯
The issue is almost always solved by creating a hair simulation cache. Maya is very stable for this, but it still needs that manual step to ensure the simulation is not recalculated erroneously in batch render. With these steps, your hair render will be flawless! ✨