Weird rendering issue

AdrianS

Okay, slightly long story. I recently purchased Marlene Bob hair. When I tested it, my render took forever. I abandoned it. Strangely, all my subsequent renders were also extremely slow, until I switched off the computer. When i turned it on, everything was back to normal. I tried Marlene Bob hair again.....same thing happened. The render after I used it (i.e. I now used different hair) I had to abandon after 2 hours at 77%. My CPU use by DAZ (I render using only my graphics card, so the CPU is overflow) was 98-100%  I switched off the computer, turned it on again and set up the scene EXACTLY as before. This time it rendered in under 2 minutes, using 45% of the CPU. What on Earth is going on????? I should mention that on both renders I re-set the render values to default. Is it possible that Marlene Bob hair is somehow doing something to settings somewhere (I know that sounds a bit like a conspiracy theory, but I'm confused!)?

magog_a4eb71ab

"The 3D mesh is made of lots of hair strands of different sizes for real-world volume and dynamic looks." <---This is quoted from the product page. When you have this kind of hair in your scenes, its going to be more resource-demanding in both the veiwport and rendering. As far as I know, you shouldn't need to restart your system(unless you've had it on for days and running different/numerous other programs). However, Daz may need to be restarted after renders when changing to a different scene to render it. If I recall correctly, this is so any VRAM on the video card that is being used by a scene is cleared from it.

Loading hair on a character doesn't change any of your render settings. Regardless of what your render settings are, loading Marlene Bob hair on your character will not change them. The CPU isn't "overflow". The scene either fits in the VRAM of the video card and is rendered on it, or it doesn't and it ends up using the CPU instead.

AdrianS

OK, thanks for that information. I understand that some hair takes a lot of rendering power and the long rendering time for Marlene Bob hair didn't really surprise me - it was the 'after-effect' that confused me. The computer had been on and in use all day, and I suspect the effect was related to the video card VRAM. My card is an NVidia GeForce GTX1080 and its 8GB of VRAM normally copes with most things quite easily.