Artur J. Żarek

You can preview environment light in COPs, but it's somewhat buggy and noisy. Whenever a parameter is tweaked in Preview Material COP, or rather whenever anything changes in the COPNet, the environment light will disappear along with the reflections. To make it reappear, one has to exit and reenter the COPNet, which will work until the next change of COPNet.

Happens on Vulkan, as well as on OpenGL viewport. Very frustrating.

Having said that, the only sane way of previewing materials that I found so far, is to keep the Karma render pane open and let it constantly render the material in the background.

I think I've hit some kind of performance bottleneck with the Tile Pattern COP. It turns out that setting Seamless divisions to 128 or more, puts a 100% load on a GPU (RTX 3070) for about half a minute. A mere change of a display flag on nodes down the stream, in a small sized network in which the Tile Pattern resides upstream, also initiates these calculations, even if Tile Pattern has already been cooked.

And if, God forbid, at that time the histogram is displayed in the Composite View pane, the full GPU load can last for several minutes, effectively blocking Houdini window.

Speaking of histogram, it seems to be recooking all upstream nodes each time I access it. Why can't it calculate the histogram just for the node with a display flag, which is already cooked?

Mike_A
I think the best compromise - for me - is ajz3d's solution above with:

Shape > Stretch Shape = enabled
Size > Horizontal scale = cos (30)

Some minor distortion perhaps, but equal line widths I think - and it tiles.

Well done, Mike! If there are minor distortions, I don't see them.
It will make a great recipe.