For some reason, a file that worked fine in the past is now giving me a rendering warning. What does this mean and how can I fix it? Thanks.

See attachment

Can you load it with asset manager?

I would handle this by starting with add SOPs for each point on the curve, add a merge node that includes all the add nodes, and then specify how these add nodes should be interpreted (b spline, bezier, linear, etc). It is easy to animate a curve that way. I’m away from a computer for a few days but will edit this to give an example file when I get back on Tuesday.

Works fine for me.

Cinema 4D does this much better, but my experience with C4D, Modo, and Houdini is that you will get much better topology using an illustrator or text file as a reference and making it from scratch. The poly pen tools of other software are better than the retopo tool in Houdini now, but next month that may no longer be true.

Awesome! Thanks.

Apparently this is also possible in Blender: https://www.youtube.com/watch?v=-0Vr3WiSJS0 [www.youtube.com]
It would be nice to have a checkbox on the transform node to scale by selections.

On a side note: transform, extrude, and edge loop cuts are probably the most used modeling tools in most 3D programs. (Maybe “bevel” as an extrude alternative in some programs). Why isn't there an edge loop cut node? Making an edge loop cut in Houdini's viewport generates a polysplit node, which is pretty uninterpretable (split locations give a percentage, but the edge designation is pretty obtuse). It would be good to have this as its own node and have an option to create more than one edge loop at different positions (like first edge loop at 5%, second at 95%), rather than just spread several loops equally. One can presently add many edge loops at one time in Houdini (which is nice) and restrict to a quantized fraction of scale (also nice), but if one wants to add edge loops at 10% and 90% positions and quantizes to 10, the first one will be at 10% and the second at 90*0.9 - which is not symmetrical (or one has to remember to spin the middle mouse button to quantize to 9 for the second loop cut).

Is there a way to create a transform type node with local action center? I can create a transform node and adjust scale and pick several polygons/faces, but they will transform globally rather than around their centers. I can fake this by creating first a polyextrude node for inner extrude and then a second polyextrude node for extrude - but this generates extra geometry. What I am trying to replicate procedurally is Modo's local action center. I can create an edit node, but this would defeat the procedural nature of what I am trying to do. Modo's local action center: "https://vimeo.com/290040078 [vimeo.com]"

The code above is very good! Thinking about your problem mathematically, the sine curve is just the y height of a particle going around a circle at a constant rate graphed according to time. So you can easily get this by starting with a hemicircle and flattening it.

Since I don't really understand the UV node used above, I'm surmising that mestela is basically using a ramp to drive the y positions. That is more powerful, in that one is not stuck with a sine function. (But I don't know why one would drive vertices to alter point position) However, if you want to use the sine function for this, I would think that you are wanting to create a sine curve and distribute the points evenly along this and then project back onto the y axis. Here is how I would do this:

I'm not sure this is what you want, but it might get you started.

Duplicating in the Asset Manager and deleting the old one worked great! Thanks.

Short of recreating a HDA, is there a way to change the default name of the subnetwork in a HDA? I can add the HDA and change its name each time, but I am not sure how to change the default. In the example below, the name of the HDA is “Studio” but it comes in as “isleofgough_studio1” and I can change the name in Houdini but don't know how to change the default in the HDA. Thanks.

The reasons for using a softbox rather than area light are:

1. ability to control direction and angle of light
2. to better replicate reflections in a studio environment.

Maybe I can replace the geolights with an area light approximately the size of the emissive portion of the softbox and make it a child of the softboxes. I'll try that to see if it works better.

Interestingly, it appears with making a geolight from an object, it uses the materials on the object and doesn't light in the direction that the portions of the object are shaded black.

Any idea about the artifacts? Thanks.

Thank you for the suggestions. I added those and the shadows look better, but the render times are awful and there are strange artifacts on objects with a principled shader. I'm not sure what is going on, but it is probably user error.

I don't think I have any diffuse bounces. They only way to make the above file actually work that I can see is to add a geolight and pick the softbox. I'm not sure why that is necessary, as the light emission shader is set to light objects.

I am trying to have an emissive shader contribute to light and shadows but it doesn't appear to do so. What am I doing wrong? Thanks.

You could use this as a start. Edit: I added a couple more steps to make it more realistic. This is the benefit of procedural modeling. You can go back and tweak it without having to rebuild the model.