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About misterbil

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  1. Volume mix cropping density

    HAHAHA, thanks Alexander! I'm actually the one that started the conversation about the looping with Peter. I'm using his technique for the timeshift, butI had a couple of issues with the blendshape where the position of both sim get jittery. That's why I was trying to use the VolumeMix SOP and was wondering if anyone had this same problem. and maybe an easy solution, like "oh you just need to switch X on" or " you forgot to do Z here". But thank you it is a very good and useful tutorial.
  2. Volume mix cropping density

    Hello, I'm Trying to create a smoke cloud loop. After generating a sim and creating a bgeo sequence. I use 2 time shifts to offset my animation and use a Volume mix to merge one onto the other smoothly. But for whatever reason the first (and thus last) frame of the result it looks as if one bounding box is cropping the volume.. but if I do a lower resolution of the exact same sim, it's all fine! I can't figure out why, how to force a certain BB to be used. help or previous related post would be greatly appreciated. PS: also attached the hip file. SmokePuff_07_V1.hip
  3. more sand/grain question

    Hi Jake, thanks a lot for your scene! I like the simplicity of it. very clean! and that's exactly what I was looking for.
  4. more sand/grain question

    I think I'm getting closer, I found out why I couldn't see the group updating in DOP .... wrong naming in the SopSolver, DUH! now I fixed that and it looks better, but I have some weird behavior at the end of the sim, Not sure if the particles are "swimming" in the texture again, or what... any idea? sandtest_forceRandom_V3.hiplc
  5. more sand/grain question

    So I tried to reproduce and change a little my file to see if I understood your process. but I'm stuck again. In the attached file I tried, in sop, to first use a pointVOP to generate color and then use a group node to generate the force_grp. And bring that to the dop network and use your technique to dynamically update the group. but for whatever reason I only get the first frame of the group. I can see my group being updating in SOP (advance a few frame, middle mouse to check the number of pt in my group, advance a few frame...etc). but I think I'm not doing something right in dop...?? sandtest_forceRandom_V2.hiplc
  6. more sand/grain question

    Hi Loudsubs, thanks a lot for your reply and file, very interesting stuff going on in there. it took me a little bit of time to understand what was going on, and how you were animating the growth (still not sure I understand at 100%):) You pointed out exactly my problem I'll bring my vop to sop level and set a group there and see how it goes. Thanks again and I'll update shortly...
  7. more sand/grain question

    As nobody answered my previous post (no hard feelings ), here I am again. I have made some progress with sand/grain but I'm still not sure of the process. In this new file I'm trying to have the sand to gradually blow away . I'm using a PopForce to move my particles and I'm controlling the v@Force Attribute with a voppop. I'm using a ramp based on Y and a turbulence noise to set the @force value as I would like the sand to start blowing randomly from the top and slowly go down the pile of sand. But I have 2 problems. 1- because the noise and the ramp are based on position, the particles enter and exit the noise/value 2- the noise is fading to quickly, I think I need to add a fit node to compensate.. but I can't figure it out. Here is my ramp/noise test (on a volume). PS: my previous post was about sand disintegration. and I attached a Hip of my scene. Please Help me out! sandtest_forceRandom.hiplc
  8. Destruction constraints question

    Hi Dennis, It would be easier if you post a hip file so we can take a look. cheers
  9. sand disintegration

    Hello, I'm trying to get a logo to dissolve/disintegrate into sand. Like it is made out of sand and something is eating out the outside shell and the sand is pouring out. In the attached file I was first trying to use a geometry and use attribute transfer to set the force of a popforce. as I would like to use in the future a more random/noisy pattern. I'm not exactly sure if my expression is wrong, if my whole set up is wrong. I tried to look around for tutorials or thread but couldn't find any. Any idea, suggestion or links would be greatly appreciated. thanks bil Sand_Desintegration01.hipnc
  10. Flow map from fluid velocity for game application

    @TheDude Peter Quint has a great tutorials about that, look for the flame loop tutorial. I use this technique all the time for my sprites. The problem with plane solution to render, per example, a smoke velocity, is that it will render a slice through the smoke, and not the outside billow and swirls. I can see this technique to work great for rivers and "plane" surfaces. But it doesn't work well for smoke. I think we are all getting close though I'm using the velocity to shade directly my smoke. And trying to get a neutral lighting with all shadows off. I need to test it in Unreal to see how it looks but it's promising. A couple of side notes: -I'm using this to replicate what Klemen Lozar is doing with fumeFX. -and also for huge column of smoke where it would not be efficient to use particles in unreal. PS: I can't believe I didn't know about this and sorry if it's common knowledge, but I just found out that if you want to use Photoshop to comp a premultiplied image, go Layers>matting> remove black matte! thank you guys for the inputs, glad to see some game people here BillowSmoke_v1.hipnc
  11. Flow map from fluid velocity for game application

    Hi Airship, that looks pretty sweet though! I'll take a look at your Hip tonight. (Just curious ) But, I was wondering, what made it complicated to use ? Thanks bil
  12. Flow map from fluid velocity for game application

    Based on the comment under his video, it look like he is doing the same thing as in games. I'm guessing a shader trick to blend between the original texture and the "distorted" images. going between 0 to 1 to 0 to 1 to 0.... The comb the normal set up is an idea developed at Valve if I remember well, you can find the pdf with the full network/tutorial online. I'll try to find it and post it here. I also need to update my previous post (on this thread ) as I found better results. Just been so damn busy
  13. Distance based ramp shader

    does this help? I'm using the point clr to tint the surface and calculating the distance via VOP. there might be more elegant ways to do this. But this worked good for what I needed. cheers distance_clr.hipnc
  14. Hello, No sure if this should be in effects or rendering so here you go. I'm trying to add some very faded fog/dust atmospheric type of fx in a scene and I was wondering how one would tackle this? My camera is flying thru it so it's a little difficult to "just add it in post", also there are some geometry that cut thru it so I'm trying to avoid the hard edge sprite cut ... trying to keep the render time as low as I can (as everyone, yes?) I'm adding a scene file where I'm using VDB from particle and doing the unified noise in volume vop thingy. But if anyone had an other quick and easy way? Again this is just to add a little "humpf" to the scene. oh yeah and the scene is big, scale wise. any help, tips, reference would help a lot. thanks and long live the houdini clan! vdb_particle_volume.hipnc
  15. Flow map from fluid velocity for game application

    Hi Loudsubs, thanks a lot for your reply! This seems like a good idea. Unfortunately I don't think this is what I'm looking for. Or at least I'm not able to get it to work. When I open your file and render an image I get, what it looks like, a single float value per point. and it is not "masked" out by the density. at least it doesn't look like it. What I'm trying to get is that if the velocity goes positive Y it get greener, (Y axe on the diagram I posted first). and redder for velocity X I'm also experimenting with Volume mix node to try to mask . maybe I can advect a bunch particles and have them change color based on their velocity... I'll try that this week end thanks a lot anyway. cheers