thoughts on hair tools

[evanrudefx]

I do not have much experience with hair other than using xgen for a bit and watching tutorials/demos of other software like ornatrix. I recently spent a lot of time learning hair in houdini and I was wondering if other people had a similar experience. 

Sops vs OBJ. I hate working at obj level with hair nodes (or in general). You have to keep diving back and forth to different objects to access data, and it's really frustrating and painfully slow. So I switched to mainly using sops. However, things were really strange there too. The first thing I noticed is that none of the radial menus work. Since you can’t really freeze hair (so they won’t be affected by the brush) you can select hair then use the radial menu to get back to the brush and only brush those selected hairs. However, that doesn’t work in sops because the radial menu and most of the shelf tools only seem to work at obj level. To brush only selected hairs, you have to click the guide groom node, click the selection arrow, select the hairs you want, then hit enter, then manually switch to the brush tool. That is just way too slow. Then, if you change the amount of hairs, your selection breaks and the hair does weird things. Changing the amount of hair going into a brush node generally works fine because it interpolates, unless you made selections in the process (which is what I have been doing). 

Some things just don’t make sense or are slow. The tools were clearly designed to work at obj level, even though you can access them in sops. 

1. Manually placing guides at sop level. I turn on shade open curves so I can see the hair width when working at sop level. When you use the guide brush tool to place guides, the guides immediately disappear. I found out that working in sops, the guide groom plant guide tool does not allow you to create a width attribute. This means the width gets assigned a value of 0 and thus disappears because you need a width attribute. The way I fix it is to unlock the digital asset and manually add the attribute. See video

2. Changing the length of the hair does not resample the width along length. This literally makes 0 sense. If I use the guide brush to lengthen tapered hair, it seems to not really get longer. However, when I rendered it my hair was much longer than the viewport. Then I learned that it's because width was not resampled to match the new length, so 60% of the hair was invisible in the viewport. To fix it, I add a resample to add a curveu attribute, then I resample the width along curveu. See video

3. Some brushes are insanely slow. The smooth brush is the slowest of them all, you can only brush a few hairs before it gets too slow to use. 

4. The brushes in general just don’t seem to work well compared to other software I have seen. They are generally slower and harder to use/give you worse results.

5. The clumping can give you different results based on your uvs, and if you update the uvs the clump node doesn’t always update correctly. I have to delete the clump node then hit undo to get it to update, or restart houdini.

6. Recaching. This is so annoying. If you work in sops, the recache menu button doesn’t work so you have to manually select all the guide grooms and hit recache. I also noticed in sops that I have to do this when I load my project, otherwise I get shown incorrect results. When working at obj this was not an issue. 

I don’t want this to be all negative so I will say this: The parts that are procedural, the guide process nodes are amazing. The guide advect tool is amazing too. You can get very good results without ever touching a brush-this is the great part.

Does anyone else have any thoughts on how grooming compares to other softwares? To reiterate, I just found manual grooming with brushes to be really slow and painful, with a lot of manual setup or switching between obj nodes.

 

 

Edited March 24, 2021 by ejr32123