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Everything posted by Fireandsmoke

  1. Flickering colours in slow Coloured Smoke

    Hi, I have a simple smoke sim using the Colored Smoke shelf tool which I have run at timescale 0.1, cached out to VDB, and am using Redshift to render. Not problems if I render a sim at full speed, but I'm noticing at this slower timescale I'm getting random flickering of my colours, the saturation dropping away to a varying degree every few frames. https://giphy.com/gifs/FfpdaTVBqu7CVlcAd8 Any ideas?? Thanks for the advice
  2. I have a node called wireframe, which takes RGBA values for a wire colour (Parameters: wireColourR, wireColourG etc) If i wanted to wire in the Cd values from points on the geometry, is there a way of adding this Wire Colour parameter as an input on the WireFrame node? Thanks for the advice
  3. Alpha channel settings for EXR into After Effects

    Yeh Mplay displays a similar alpha, but with all channels on it creates an image like in my post above, whereas AE/ Prem do not, the image has far less detail. Maybe this could also be a Redshift thing.. I dont know yet. By changing my AE settings to the following I can get the image to look similar, but whatever I export still seems to have the same alpha issue once in Premiere. Perhaps this is starting to be more of an issue for an Adobe forum, but I just thought there would be some people here who have a simple answer, given this must be a very common workflow.
  4. I'm having trouble deciphering the correct workflow for importing Houdinis EXRs into AE and then out for edit in Prem Pro (EXRs are exported from Houdini/Redshift with default settings). It seems like the alpha channels are very weak, and leaving nearly my whole image transparent. Does anyone have a tried and tested method which they could share for bringing Houdinis EXRs into and out of AE, for an export into a format like ProRes 444+alpha? I've had a look at a few posts online and played around for hours with countless colour management and alpha premult settings within AE but feel like I'm banging my head against a wall. Ive attached the EXR and a Mplay vs Prem comparison. Thanks for any advice ExampleEXR.exr
  5. Very useful attribute when doing anything that involves rendering particles or copied geo. I use it endlessly. For example, it can uniformly change the size of your particles, by creating a wrangle and adding @pscale = "insert float value here" And beyond that add noises etc to the pscale value in VOPs for interesting effects. Remember as well that when copying geo to points the pscale attribute will also affect the size of copied geo if "Copy Point Attributes" is selected in your Copy to Points SOP.
  6. Reference geometry filename in export filename

    Thats great, thanks for your help, much appreciated
  7. This is probably a fairly simple one.. I have a geo sequence which I want to convert and export into a different format. I would like the filenames to remain the same as the original geo, (apart from the new filetype suffix). How would I reference the name of each frame of the original geo sequence? Thanks for the help
  8. Hi. I have an interesting problem I've been trying to solve for the last few days but still haven't managed to find a good solution. I have a sequence of geo which has been captured with a depth sensor. One of the issues with the sequence is that the point numbers change positions every frame. Whilst there is a rough order to the point numbering per frame, its not very consistent. I'm wondering if there would be a way to homogenise the layout of the point numbers by reordering, or to somehow re-mesh the geometry sequence to create a new version with more of an ordered structure? I've attached a short bgeo sequence as a sample if anybody would be interested in having a look. Thanks for any advice VolumetricTest.rar
  9. It's quite common that Ill set off a render at night only to find out in the morning that it has crashed at some point a short way through. Generally, if I simply restart houdini and render from where it got up to, it will continue without problem. Not sure why this happens, but it does mean over night renders are often a gamble. What I'm wondering is, would it be possible to have some kind of script which detects a crash, reboots houdini with the working project and takes off from the last rendered frame? Would such an idea even be possible?
  10. Script to resume crashed render

    Thanks for everybodys input. Ive ended up going with the free version of Royal Render, and it has been relatively easy and effective to setup on a single machine, and I have very minimal networking skills. For whatever reason, I was finding that the rrSerivce was not resuming my renders on a system restart, so I placed the win__rrClient.bat into the Windows startup directory to force it to start.
  11. Script to resume crashed render

    Thanks. Do you know if the free version of Deadline has this functionality?
  12. Convert tris to quads

    As a side note to this which may help someone in the future: if youre wanting to render a wireframe quad look (which is what I was after), using Redshift selecting Rendering an object as Strands will automatically render the wire frame as quads.
  13. Convert tris to quads

    Hi, Im wanting to render a wireframe look of a scan captured asset, but Id prefer to lose all the diagonals and have it in quads.. is there a simple way to convert tris to quads in Houdini 17.5, I cant seem to find it? Thanks
  14. Convert tris to quads

    Cool, thanks for the help
  15. Redshift Proxy Workflow in Houdini

    So does that make the above instruction now irrelevant?
  16. Flickering colours in slow Coloured Smoke

    Ha..! I will have more of a look tonight as well. Very easy to replicate the problem, just lay down a coloured smoke (via shelf), and gas upres it (also via shelf). Youll see straight away that the upres smoke is black. -J
  17. Flickering colours in slow Coloured Smoke

    Thanks Jesper. Nice try but no cigar unfortunately!
  18. Flickering colours in slow Coloured Smoke

    Well Ive worked out where the problem was coming from, but damned if I know why.. maybe its a bug. For Redshift to render coloured smoke, you have to convert the volume to a VDB (among other things). And basically I'm getting the error if I cache out to VDB and then load the VDB back in and render. If I cache to Bgeo, and then do a the conversion to VDB at render time, no problems. Iv'e been playing all even with the GasUpRes... I LOVE it! It's the first tool I've used in Houdini that makes timescaling a sim do what I want, I wish I'd looked into it ages ago. One question I have, which maybe by chance you can answer... I'm trying to use Gas UpRes with the Colored Smoke shelf tool. but the color is not transferring to the upressed volume. The volumes are created but the Cd values are black. I found a hacky way to use Volume Mix to mix back in a frame with colour from the low res smoke, but I'm wondering if there's a better fix...?
  19. Flickering colours in slow Coloured Smoke

    Will do! It currently imports a reasonably heavy vdb and requires redshift, but the sim is still in there so you can see the settings I used. Thanks Jesper, much appreciated. Ill start looking into Gas Upres and substeps tonight.
  20. Flickering colours in slow Coloured Smoke

    Its at home so I can't double check but 95% sure it was temp
  21. Flickering colours in slow Coloured Smoke

    Ah ok, excellent. I will have a look at that, thanks. When you say cache out subframes, does this have to be done as a .sim, or can you cache subframes into .bgeo or .vdb? My understanding was that a large purpose of the Retime was to avoid having to do all this, relying instead on the method of interpolation (aided by advection), so I'm still curious as to why I'm getting such severe errors (basically its jumping back to some kind of rest state at 5 frame intervals (retiming at a 0.2 speed)). Not to hijack my own thread, but whilst a Retime approach may work, I'm still also curious as to why my original problem is occuring with the flickering color, if anybody has a theory about that...?
  22. Flickering colours in slow Coloured Smoke

    Well I would have thought so, but I've been having plenty of issues with the new Retime node.. I posted about it on sidefx forum but nobody has replied, I keep getting very jittery results such as this: https://giphy.com/gifs/69EhNTJHxxpfE6vHU8 My post is here: https://www.sidefx.com/forum/topic/59932/ One thing I have not been doing though is adding extra substeps to my initial sim. Is that a requirement for a velocity advected retime? And is so is there a relationship between the number of substeps required and the desired retimed speed? Any advice would be helpful, I haven't been getting very good results so far!
  23. Apply detail to smoke using Volume Procedural

    Not sure what you mean to say... if you blank that out, then its just rendering the volume without the procedural.. so naturally it will render the smoke. This issue I'm having is with the volume procedural applied, how do I import that density of the existing smoke into the cvex shader, so I can use the volume procedural to augment my existing smoke.
  24. Hi, This is probably a simple bit of VOPs, but I can't seem to get it. I'm wanting to use a Volume Procedural to add some detail and noise to a low res smoke sim. When I add the noise to the cvexvop, driven by the P and output as density, it is creating noise but filling my whole bounding box, because obviously its adding density driven by noise at every position. How would I restrict it to apply only to the existing smoke, or use the smoke density as a mask? I thought that by first multiplying P by the density would work (such that where smoke density equals 0, no noise would be added) but does not seem to. Thanks for the advice volumeprocedural.hiplc
  25. Apply detail to smoke using Volume Procedural

    It does appear from some reading that when using the Volume VOP Global Parameters inside the CVEX vop it will not import the density of the subject volume, it rather is a blank canvas. So the question is then, how would you import the density of a volume into a CVEX vop?