I'm having trouble with an animation around 100 frames long to render which is taking almost 1 hour per frame to render, and need help in modifying my approach so that it doesn't take any longer than a day to render a few seconds of animation.

I'm using Redshift to render for its speed, as over this year I am going to be creating a lot of animations that have to look good in 1080p, as part of a Masters in Architecture.

At the moment I'm trying to animate a wire that grows through and over a hand, which erodes the hand. I've used a basic setup of VDB subtracting with the wire and a mesh of the hand I modelled which has been cached, and the animation is looking good.

Problem is, as I need to be able to see the wire through parts of the skin where it pierces, there needs to be a degree of refraction. The materiality is to be a slightly translucent silicone. I used the skin shader before and liked the look of it and was reasonably fast to render, but I need some translucency on this now.

The actual render time is around 15-30 minutes per frame which I can live with and can probably optimize a bit more to make it faster, but the loading for the redshift scene before the render even starts is taking 20 minutes. I'm not sure why this is the case, and what I can change in houdini to make this faster. For me it is almost impractical to render frames if it takes any longer than 40 minutes per frame, where 10 minutes a frame is the most ideal situation. I've looked at redshift tutorials to try to optimize the render settings to no avail.

Some insight on why it is taking so long and potential fixes would be great, so I can think about how to set up the model and shaders properly and not get any nasty suprises near dealine! I've attached a link to the houdini file with the cached files so you guys can look at my settings, with a frame from another clip showing the effect I want to achieve.

https://drive.google.com/open?id=11MxVNHP_ZEXASvyFFR905Z22tSsIeRlm [drive.google.com]