- We don’t have any prebuilt samples that use other lights, but we do support point lights. Please take a look at Grid3D Bake Point Light and follow the pattern we use for directional lights in the templates.
- No, the fluids can’t be shadowed by geometry yet. This is in the works.
- We are looking at various formats for baking out our simulations.
Thanks for the info!
Was also wondering if support for playing back a baked VDB sim coming from say Houdini is planned?
No multi GPU support for now. It should work in VR, but you need to be conscious of performance, for sure!
I’d have to see what you mean with the occluded foliage. To work independently from the camera, you can make it non camera facing with a checkbox on the system, or look into 3d sims.
We are not currently doing network replication for realtime sims. Your best bet is to run the sim on all the clients, but it isn’t guaranteed to be exactly the same given framerate variations, etc.
Yeah, this type of thing sounds doable! It’d maybe be a combination of fluids and general particle simulation within Niagara. It sounds like it’d be a neat project.
Yes, you can advect particles around using the velocity from the fluid simulation. There is a template called ‘Grid 3D Gas Particle Advection’ which does this.
The particles can then be manipulated like any other Niagara particle. All the standard modules and attributes will work the same way.
Yes this is a known problem that we are working on.
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This is an ongoing area of research. Live simulations often react unexpectedly as the time steps (many during shutter open, only one during shutter close) vary as temporal samples increase.
For the time being, the most reliable way to maintain the same look is to use a Fixed Tick Delta Time. You will find this option on the Niagara System node (the blue box). Set it to 1/30 (for a 30fps sequence as an example). This will force the simulation to tick at the same rate no matter how high you set your temporal samples.
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Ahh excellent thank you! I have just given this a try and it worked very well for my cinematic, thank you! I went with 1/24 as Im rendering movies, I love that I can at least put in a few hero fluid sims now, and bake out the rest!
No, the current rendering setup does not have the option to allow fire to emit light directly. Having said that, you have options to add lighting influence into your scene depending on the type of effect you are looking for.
In most cases the illumination can (and usually should) come from a proxy of some description, something low frequency and cheap to render so as not to introduce flickering and high render times.
The engine supports screen space GI and reflections. The material attached to the fluid simulation will work with these methods.
Lumen supports the idea of ‘scene capture only’ actors (it’s under Advanced on static mesh components for example). This means you can add a bright material to a simple mesh and have it contribute to Lumen without it appearing in your camera render. There are the usual limitations with Lumen (static actors, solid opacity etc) but it can give a non-screen space limited influence into your lighting.
You can obviously attach a point light to your Niagara actor, but you can potentially go one step further and advect particles within your simulation, then pass those positions back to a blueprint and spawn lights accordingly (probably overkill due to it’s complexity of setup, but could be interesting to try. There is an example in the Niagara Advanced hallway in the Content Examples project which demonstrates how to pass particle data to BP).
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It seems that currently fluid simulation does not cast shadows correctly. They do indeed seem to support shadow casting from directional lights when setting “Volumetric Translucent Shadows” to true but the shadow cookie has incorrect perspective relative to the rendering camera. Any plans for supporting proper shadow casting for Fluids?
Trying to render flip tank simulation in MRQ with no luck. Looks like all calculations don’t work. Trying to set Niagara’s lifetime & desired age doesn’t help too.
But everything works in Movie scene capture
UPD. Find out that if I add solve force & velocity everything starts to work, but all physics now incorrect 