Houdini for Beginners - 004 - TIMJ - Particles and Volumes

hello and welcome back to a new tutorial first of all i hope you're all good and i hope you will all get a good new year few days left then the year 2020 is over and i wanted to make a new tutorial about houdini for beginners 002 so the second part to deal a little bit more with particles and that we will do today in this tutorial but first um i received an email from cg circuit and there is a year's end sale so the final say and with the code end for the year you will get 40 of all the tutorials and yeah this is the code here enjoy the code and check out the tutorials the link will be down in the description via my home page timjaydesign.com okay i will make a link in the description and without further talk let's do this so i wanted to go a little bit more deeply in the particle because i really like particles and you can do a lot of cool stuff with that and we will start with a simple geometry container so press tab and type in geo or ge and the geometry node will pop up and you can select the node and place it down we will call this pds for points and let's call this underscore sim so point sim i will give it a round shape and the black color cool we will dive inside with double click and we will place down yeah we need a initial state for our simulation and i will place down a simple sphere for the beginning the cool thing is we can later switch them i will give it some divisions here so frequency bump it up to 50. and after that i will place down the null because i want to stay organized for larger setups i will call this in underscore emit and we've now got our emitter for the particles i will scale it a little bit down so uniform scale to 0.1 now we got our sphere and our null node that's basically a placeholder so we can stay organized so after that we want to place down a pop network the pop network will create a little predefined particle system and you can already see we've got particles and when we hit the up arrow key or the play button we'll see that particles are spawning on our sphere that's cool okay now we can dive inside our pubnet and let's call this simulate pts dive inside and we've got a really important node up here that's the source and the source will determine how we will scatter the particles on the surface or what points we will use and how they will get birthed so for example they will currently get birthed per second 5000 per second so in the frame range from 1 to 24 5000 points will get spawned and these points for example will lift 100 seconds and the life variance is currently at zero but when we bumped it down to one and set the life variance to 0.25 the particles will live one second with imperfected a life span of 0.5 seconds so you can see they will despawn or they will die and you will get this yeah really cool um pretty like branch movement kind of thing so that's pretty cool on the sphere but we want movement and let's start it up here back to 100 so the particles will lift longer you can include movement with for example i showed you in the last tutorial with pop wind pop wind in here with velocity and uh uh x um yeah x erection and you will get something like this you can then pipe in an amplitude and you will get something like this also pretty cool so what you can do now for example that's a really basic example but dollar ff equal equals one so we will only emit 5000 points at the first frame dive up let's emit 5000 points at the first frame and that's basically a thing you should do when you first use houdini the first time placed on a trail get it on connect this polygons tray length to your timeline length and deselect close rows and you will get this yeah pretty cool line growth so really really simple but it's a pretty cool start point for a first simulated setup okay we did that let's get back to our network here and what i want to do i want to make a custom force so we will dial it back to zero and impulse count zero constant activation make it on so one and constant birthrate let's deal with 2500 points per second so we will now simulate 2500 points per second and we will got a win for force so x y c let's make it to the y direction so they will go upwards and you for example you can increase roughness so you will get a really yeah and tropical growth with a really high entropy but you can already tell the roughness go back to 0.1 and you will get this really cool organic swirly look cool but now we want to use our own little fourth system and we will do that with volumes we will select our sphere we'll place down a box and when we get the input into the box we'll basically yeah get the bounding box of the sphere there's also a bound node so that's basically the same thing but on the bound now the cool thing is you can yeah increase it increase the size with the with the box you basically can do a simple transform and then transform the uniform scale a little bit so that's fully up to you i will use the bound for now and we will create a volume based on volume we will make it a vector volume and call it well for velocity so we can already see we've got an empty volume with velocity 1000 by 1000 by 1400 voxel with a voxel size of 0.026 but we will increase that so type in for example 150 and now we've got 3.3 million voxels roughly on each axis okay after that we'll place on a volume up then we will get our position and for example use the standard call noise and pipe that curl noise out so bind export to our velocity so at bell um currently nothing will happen because we bind it out as a float but a three-dimensional waves got always three vectors so we'll choose vector for that so bind that out and now we've got our velocity volume here and we need to increase the roughness so the frequency let's pipe it up to five five and five and now you can see we've got a volume field here and we can visualize this volume velocity field with a simply scatter or with a volume slice volume slice and a volume trailer so you can pipe in the scatter and to the first input and the volume into the second input and you can already see this is now the volume or the velocity volume visualized or you can do it with a volume slice that's basically the same thing and you already get a pretty cool other kind of growth with this lines and a static growth of course you can animate it with curves and so on but a cool thing is with that you can visualize the volume and you will get a feel of it and you can see it how the lines will move and so on so you can do a rendering with that with lines that's pretty cool but what we want to do this is just for visualization let's place a novel here this out [Music] let's make other kind of color so this is a visualization of the volume velocities okay now i piped in the volume warp into the input number two and what we want to do we want to place down a drag by volume pop attract by volumes get to the second context geometry this is the second in input so our volume is on the second input and we will get the velocity volume in and we can choose for example update velocity and now when we play our uh our simulation we can choose here different parameters let me just get updated velocity and we will do that yeah a little bit bigger let's increase our bounce to 0.5 0.5 yes copy the parameter and paste the relative reference here paste relative reference paste relative reference and paste relative reference cool and now you can see we will get let me just i want that's right you can try different uh different velocities out but i will choose a lower frequency here and you of course can try out other noises for example and now you can see we will attract our points with our volume here that's pretty cool you can choose update position i usually choose update velocity or you can update the force that's that's fully up to you and you can play with the velocity scale and now when we place down our we just get here duplicate of our input and we will change that back to our emit on the first frame 500. zero and zero got an error here okay yeah let's just do it with that pulse count maybe 500 points zero zero so we will only emit oh dollar ff that was the arrow so we can change that back here to 0 and 0 and 1 and 500 for example so we will now image 500 points on the first frame and the cool thing is you can now for example use the trail and trail them back and let's check the bounce okay we can make the bones much bigger let's use a value of two let's have a look at the simulation here okay cool and now you can see we've got a really cool growth here but the growth is currently limited to our square or box and we can change that of course too for example let's get a sphere and we will make a bounding box with the sphere and off the bound so you can see let's make a wireframe we've got here our our initial bounce here and we will cut the sphere but we want to transform the sphere so the sphere will fit the bounding box a little bit for example 0.5 scale and now what i want to do i want to create out of the sphere i want to create a volume um vdb from polygons and i will call this vel for velocity and i pipe that into the second input i will get in here and you can see our yeah velocity volume is basically a box but now i can do a volume sample so we will look up our position from the voxels from the second input our sphere and i can multiply that with our current curl noise and we will get now a volume that is limited to a sphere of course you can you can basically do it like like directly a sphere to bdb that should also work i think oh yeah yo yeah it's currently only one uh it got no directions but you can do that like so too but i think that's a pretty cool way because you're yeah in a pretty cool workflow let's just re-enable here the subtraction because you can influence your position your geometry so you can place down a displacement modifier for example on and so on and so on and now when we will grow our sphere our setup here it will get limited to the sphere shape so you can already see on that direction here it will get limited and i think that's a cool thing of yeah limited growth system and you can basically pipe it into any form so you can displace the sphere you can let's make one thing let's make it a little bit smaller um for example you can do something like this so i think that's that's pretty powerful to limit the growth okay cool so we've got our particles and our trails let me check the time okay and you can limit your growth now now and another thing is you can play with the with the different noises so currently we've got our let's go to our visualization that looks pretty cool too but what you can do let's get another noise here for example a unified noise static position into position we want a 3d noise and i want a cellular noise for now and we can pipe that out and play with the frequency a little bit let's just check out different noises here alligator or we can use we can use the ntls noise that's pretty cool too or we can use a double anti-ls noise some anti-anti-ls noise and pipe up we can pipe up pipe down the the roughness here but pipe it up here a little bit and that's of course fully up to you how you will reach your research or do your your r d on on that kind of stuff and we can place on a constant and this constant will determine our frequency here three floats vector and two copy parameter pass relative reference two by two by two and now you can have a look how this will look so for example you you will need a longer time for for a different approach of course we can make that much fuzzier and much higher and another cool thing is what we can do [Music] we can do basically a scatter into our volume here so and use that for example for the input points or we can use of course much more and we can give them a little bit of variance here variance that's on okay and now you can extend the timeline and grow more and more and more and you will get pretty cool forms out of this and i think basically in the end it's it's it's fully up to you how you will get determine your look or your style uh your noises and so on and um a big thing looked af with rendering but i think that's pretty cool approach to new forms and yeah meta material stuff like that okay let's do what we can do we can do um connected json pieces so that's another cool thing what you can do and you can make a resample i think let's resample the whole thing here resample it we get a lot of points and you can smooth it with with attribute blur should pretty good but with proximity smooth and yeah you will get pretty s smooth um connections here so that's another cool thing to do just use so that's another research area here you can smooth them you can manipulate them okay and of course that's fully up to you connectivity is bad proximity is better proximity radius what's that max neighbors oh okay now we get the juicy stuff yeah cool and of course that's that's fully up to you you can place that again a subdivision and do like these smooth connections and you can uh get a few out to get a little bit more depth or feel for the object in the viewport you can visualize the curve view here cool so we did that and on my um youtube channel they're pretty uh rendering pretty much um a good amount of rendering videos about lines um you can watch them and then play with your own setup but i hope for beginners that's a good tutorial to get a little other kind of thinking and to play with the stuff so you can do it with lines or you can render it as points or you can oh yeah one more thing you can do a vdb from particles that's another pretty cool thing in my opinion 0.01 we will need a larger point scale or smaller point scale 0.05 2.005 and 0.85 let's do let's just get so you can basically do it with both setups but i will just use that setup for now here and the cool thing is you can now convert basically your your lines or your basically your points into geometry convert it back so convert vdb or simply a convert node convert it back to polygons and now we can smooth the hell out of it just to give you an example what's all possible 250 and you will get something like this so that's another pretty basic example but i think it's pretty cool and yeah feel free to explore the setup building build it up to your own and i think you will get some pretty cool interesting ideas or setups and just yeah pipe that in here okay we need more resample here let's move that and i have a look looks like a bacteria yeah and you will get these sweet connections here so all fully up to you the limits are endless and just try to find what will work for you for a setup for your client for your project and so on so i hope you liked it and i hope you will get all a good new year and check out cg circuit the discount instagram twitter um homepage youtube channel and i will get to you back at a new year when a new year is 2021 i think in january there will be new tutorials new courses and much more so stay safe and i will see you you

Channel: timj design

Views: 12,973

Keywords: houdini, rendering, sidefx, tutorial, redshift, octane, cgi, vfx, motion, design, motiondesign

Id: WySzeEniScs

Length: 32min 36sec (1956 seconds)

Published: Sun Dec 27 2020