UE4.20: Niagara Realtime Butterfly 01

Real-time butterflies niagara system use static mesh render and vertex animation texture (VAT)

Niagara system and vertex animation texture enable a large number of particles with animation and also very much optimized for high FPS in the game engine. For previz purpose or even render purpose are both work.

VAT Vertex Animation Texture

It's really efficient and low GPU usage to render a shader with animation data in the textures. VAT stands for Vertex Animation Texture is using this technology. Especially in this case, simple animation and high numbers of the same animation object.

Here's the VAT look like on the right hand side. And how does it work? In 3D modeling, animation refers to connecting different states of an object at different times (such as position and color) in a continuous sequence. On the other hand, in 3D modeling, vertices of an object are used to store information such as position, normal, and color. These vertices are then connected to form lines, which are in turn connected to form faces, resulting in the 3D object. 

Unreal Engine 4.20 Niagara System

Unreal_BTF_Ctrl_03.mp4

Compared to Cascade Particle System, Niagara System has much more flexibility to create dynamic particles.

In this case, particle movement is running a curl Nosie which we often use for VFX noise force. The particles velocity is driving by this force and also change the direction. In addition, there are two more forces used in this system, which are Point Attraction Force and Drag Force. 

Point Attraction Force keeps the particles coming back to the center point. As long as they are close to the center point the force will decrease, vice versa, particles go further the point attraction Force will increase. 

Drag Force slow down the velocity until the velocity is 0, which is helping the particles to turn back to point center.

Niagara Module Script 

This module script opens up a much easier way to create customize effect. WIP

Last Update:  Octorber 28, 2019

Software: Unreal Engine 4.20

OS: Windows 10

Specs: GTX 1060, Intel 8700K, 64GB RAM


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