Thank you so much! I didn't realize you have to assign the density attribute to density. Didn't it use to be automatic based on the name?

Unfortunately, the Labs Instant Meshes doesn't work on Catalina either. Only about half the Lab plugins will not crash Houdini.

The scatter is set to “by Density” and the scattered points have density as an attribute. They don't actually scatter by density though. Bug?

I'm sure this is an easy solution, but I can't get the Attribute paint to work properly with scatter. It used to work well with the old paint SOP. I'm using the most recent version of Houdini and the Attribute paint seems to correctly assign density (when viewed in geometry spreadsheet), but that is not reflected in the scatter. It is probably a stupid mistake, but I can't figure it out.

Has anyone gotten the Lab node for Quad Remesher to work? I tried downloading a trial and consistantly get a crash with the exoside_quadremesher node. I have the Lab installed (the GameDev replacement). It is not the model, as I get the same crash just modeling the pig head to the exoside node.

Update: apparently it does not work on a Mac.

I haven't seen the tutorial but
@P = @P + @v * @TimeInc;
Should not have a plus before the equal sign. You could add to the existing value of the position coordinates by:
@P += @v * @TimeInc;
That would give the same result.

Yes, so long as income <$100,000

Just to give a follow up: I purchased the 16 core version of the Mac Pro and render times with Mantra are in minutes rather than the hours it took before. I had to reinstall and activate 80+ applications that I use fairly regularly (most in graphics arts). The only issues were with Windows 10 on a Parallels partition. Windows got corrupted with an Office 2016 installation. Microsoft refused to reset activation on the office product, as they wanted me to move to Office 360. Then Windows itself lost internet access and could not be fixed. I deleted the virtual disk and created a new one and Microsoft would not activate Windows 10. I went through the usual troubleshooting and ended up with tech support five times with phone calls over 2 hours total to get this resolved. I now remember why I moved away from Windows. All the Mac side worked perfectly from the beginning.

I don't say this to imply that Apple is good and Microsoft is bad. I worked strictly on Windows computers all my professional career. I realize a Windows machine is more powerful and cheaper than an Apple system. But it is a breath of fresh air to have Apple's stability. Even when there are problems, a first aid or reboot fixes problems 99% of the time. In Windows, the solutions are time consuming and often incomplete. In the end, I am very happy with my purchase. If I only used Houdini, I understand why the Mac Pro is not ideal, but I am not in that category.

Buying the minimal RAM and upgrading yourself seems to be what everyone recommends.

Thank you. So are you saying that the processor will be slow regardless? Would 16 core be appreciably faster for mantra rendering in the absence of fluids or complex simulations? Apple overcharges for RAM and that would be the easiest to upgrade at a later date, but I was thinking of 48 GB which is the minimum recommended by Avid.

Yes, mantra. Most of the renderings I do have fairly simple models but environmental lights with additional studio light setups and high definition textures. I do use other programs like davinci resolve, so I am trying to balance needs.

I regularly use over 80 software apps, including three which are windows only (via parallels) and don't wish to change operating systems at this time.

I am trying to keep buying a Mac Pro under $9000 with discount. I burned out my iMac from probably overheating with many days of rendering. If rendering models with high definition texture maps but little simulations is the goal, would it be best to upgrade the processor from 8 to 12 cores, expand RAM, or upgrade the graphics card to a Vega?

Try Varomix's lamp tutorial instead.

I would like to create some animations for tying knots. If I use a curve (set off controllable null positions) and use sweep, I can create great still images. But if I want to animate this, the curve length is not constant and this creates flaws in the animation. I want to keep the ropes very smooth looking (the way I can with 500-100 resampled points on the curve). Would it be best to create 500-100 bones and animate that or to have the rope be a cylinder and have it deform to the curve?

Varomix has a tutorial on VEX. I haven't purchased it, but his other tutorials are excellent for getting started. https://www.mixtrn.com/nature-of-vex [www.mixtrn.com]

Thank you for your time and expertise. I see how this renders quickly and would be a much better solution for an animation. I'll see if I can incorporate some of the ideas. I can't change the sutures to bgeo files, as they will change position with the animation. Is there an advantage of saving most of the geometry as bgeo files rather than just freezing the terminal null? More importantly, I'll have to look your modified shaders in the SHOP, but they do render fast.

Before seeing your post above, I appreciate the tip that the primary problem with my renders looks like the sheen. Just changing this to zero made things a lot better. I changed the GGX to Phong, but had to tweak the reflection settings to get a better approximation of the original GGX. That improved render time about 20%. Your shaders above are very fast.

Thank you. Those suggestions helped.

hmmm. I'm using the default guassian filter for the texture. Here is the hip file and shader.

I have a still render that has noise, particularly in the area of a texture that has normal map, but also in reflected areas. I would like to animate the file, but before doing so, I need to fix the noise. The still is rendered as an 8 bit 2500x2000 Tiff with gamma 2.2. It takes about an hour and a half on a Imac 2017 and it has more grain than I would like (see attachment). How would I improve this without significantly increasing render time?

My current Mantra render settings are:
Mantra tile size 48
Reflection limit 4
Refraction limit 4
Diffuse limit 0
Color limit 3
Ray tracing Bias 0.001
Sampling pixel sample 5x5
Gamma 2.2
Min ray samples 2
max ray samples 8
noise level 0.001
Global quality 2
Diffuse quality 1
Dicing shading multiplier 2

Since all the steps to create the geometry was deleted, for safety, I would click on the node and save as bgeo or obj. At least you won't loose your model, though you lost the steps. I would look through your backups, though, so see if you can find a model that had the steps.