It is developed as a part of FluidDyn project, an effort to promote open-source and open-science collaboration within fluid mechanics community and intended for both educational as well as research purposes. Hopefully, you'll see the flipbook playing in the viewport (see pic below).The Python package fluidsim is introduced in this article as an extensible framework for Computational Fluid Mechanics (CFD) solvers. Again, under the Link Inputs / Output, SampledColor (carefully, the output of the disabled SampleTexture module is also on the list - do not pick that). Pls add a Color module with the green plus (+) besides Particle Update, select the module, and (using the tiny arrow rolldown menu) besides the color input fields add the output of our flipbook player module as Color input. Like in the previous case, we'd like to have a color-preview. This continuously growing value is going to induce the frame-to-next-frame jumping (playback) on the flipbook. At the top of the module details, click on the tiny arrow beside the "Phase" row - and type "time", select Engine Time. Pls go back to our custom Flipbook reader module, hover mouse to an empty area in the UV row, right-click, Paste. This operation copies the whole hierarchy under the UV-row to the clipboard. Pls select the Sample Texture module, hover your mouse over an empty area in the UV-row (below the texture options). We are going to copy-paste the UV setup that we have done for the Texture Sample module last time. Pick the included velocity flipbook as Texture input (T_Fluidninja_Velocity_Flipbook.uasset). Going back to stack view: select our custom flipbook-reader module. Create a flowmap and drag it to Unreal Content Browser to start developing! I made a simple, round, clockwise brush stroke - this flowmap, describing circular flow will be the sample data for our first system. You could also preview the animated flow. I encourage you to download the tool and play a lot! By toggling the FlowLines and VertColor flags you could visualize the above-mentioned vectors and colors. We don't need a fluid simulator to make a single flowmap - thanks to Teck Lee Tan we have a simple, stable, free, 7 Mbytes piece of software to hand-paint such maps: FlowMapPainter v0.9.2, up since 2012. A velocity flipbook is a sequence of velo maps, describing the temporal changes in the velocity vectors of a fluid system. We are describing motion data with a 2D vector-field stored as texture - this is the concept of velocity maps aka flowmaps. Imagine stirring a bowl of liquid, and making a picture / snapshot of the surface from the top, and assigning red and green values to each sampling point on our picture depending on the velocity of fluid movement at a given point. Vertical movement is green: 0% up, 50% standing, 100% down. Horizontal movement is described by shades of red: a value of 50% means we are standing, 100% is full speed right, 0% is full speed left. Imagine that we are moving on a two-dimensional plane and our moving direction and speed (together called velocity) are described by colors. Creating a Simple Texture Sampling Emitter Unlike classic baked VFX, our systems could respond to physics. Instead of overwriting intrinsic velocity, we are pushing particles to sim defined directions while allowing collisions with scene geometry. Maybe the most spectacular example is using velocity data from a fluid simulation to accelerate particles. The point is that we are altering particle behaviour and not determining. Unlike geometry texturing, "particle texturing" should not be a one-to-one topological mapping between the texture space and the particle-space: fluid data could (1) provide initial conditions for a dynamic simulation, (2) drive abstract parameters or (3) used additively. We could drive masses of GPU particles with fluid data. Niagara provides an alternative use case: utilizing the Sample Texture Data Interface, we could directly sample fluid data with Niagara modules (no materials are needed) and interpret the texture-stored values as float / vector / color type variables to drive arbitrary particle parameters.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |