Trail SOP Question

I’m trying to make use of the Trail SOP but I’m having a hard time figuring it out. I’d like to achieve a similar effect as the example with the box on the Wiki, but I can hardly get close to the same effect that is shown there. Can anybody help me with this?

The Trail SOP is beautiful, but it’s not very efficient for most geometry types:
base_trail.tox (1.59 KB)

An alternative would be to use the trail SOPfor instancing:
base_trail_for_instancing.tox (1.84 KB)

You could achieve a very similar effect by trailing in CHOPs, though that’s a little stranger to get organized (though it is much more efficient (0.15ms vs 0.5ms).
base_trail_for_instancing_trail_in_CHOPs.tox (1.72 KB)

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Generally speaking. In touch you want to do as much transformation, rotation, and deformation as possible at the Geo COMP level. Just about everything that happens at the Geo level is handled by your GPU and as a consequence much faster. SOPs, on the other hand, are currently CPU bound (though someone is going to crack this with the C++ SOP I’m sure).

If you can, it’s good practice in Touch to think of your SOP pipeline as one that cooks as little as possible. There are, of course, exceptions to this idea but it’s generally good to keep the animation of SOPs as lightly touched as you can help. Some exceptions here would be the new Alembic SOP, and the Blend SOP - blending between existing geometry is generally faster than making changes to your procedural network (not a hard and fast rule, just on observation).

Thank you! I definitely have a much better understanding on how I can use the Trail SOP and I really appreciate the examples, super helpful, the CHOP one is really eye opening. I do wonder if in that the photo I posted is creating a spline like Trail; like I see from stuff from C4D and Houdini, I know that it might be taxing on my rig, but I just want a complete understanding of what the Trail SOP is capable of, if that makes sense… It also, from the description of the photos in the Wiki, seems like its using the setting ‘Connect as Mesh’ because it mentions its connected by Columns. Would love some input on that, if you could!

Hey JeffJ,

I think the trail SOP is a carry over from the fork from Houdini. Every time I sit down to wrestle with it just ends up feeling clumsy. Anyhoo - looking at the photos and wiki page it’s pretty difficult to tell if it’s individual copies or a single mesh that’s constructed out of past frames. I don’t use this one much these days and have instead focused on GL and vertex shaders to get the fast deformations and transforms that I’m after.

That aside, the best way to learn about any of the ops is to play with them and look through op snippets (it’s in the help menu and a great way to see examples of how to work with lots of different operators).

What’s the effect you’re trying to reproduce? If you’re looking for something similar to David’s work:

instagram.com/p/BYd7GbjgKyp … avid_braun
instagram.com/p/BYgZIwwgA6Q … avid_braun

or Vincent’s work:

instagram.com/p/BWyZwO_nTXr … cent.houze
instagram.com/p/BV5BfVCH0jT … cent.houze
instagram.com/p/BVm0cQ2HFGN … cent.houze

It would be worth digging in on some GLSL to beef up your shader game - that’s where lots of the real power of Touch really starts to shine.

What are you looking to make? Sometimes it’s easier to give folks a push if you can talk about where you’re headed / what kind of art you want to make.

Hey thanks for your quick response again, I really appreciate it! I guess what I’m focusing on at the moment would be stuff like from the latter two of the two examples from Vincent, but I’m actually familiar with all those examples from Instagram and would love to do stuff similar to all that in the future, and I know that GLSL is the next logical step for me to learn going into Touch, but I feel like there is still a ton of content I can create using just whats available in nodes in Touch, and admittedly GLSL is a bit daunting, even though I have begun to dip my toes in it. That being said to answer your question, what I’m really going after here is using Realtime data from my Kinect 2.0 to do whatever the most amazing stuff I can in Touch might be, definitely going for combining performance art [various forms of dance mostly] with art from TouchDesigner, at the moment at least.