Rendering slices of pyro

[5DNick]

Dear Forumers,

I have a project where I am combining slo-mo explosions (from Houdini Pyro) with a few different parts of exploded sci-fi drones (that are comic book style, illustrated by someone).

I want there to be depth to the final output so I want to slice each pyro into 3 or 4 segments (perpendicular to the camera's LOS), so I can put the segments on top of each other with the drone wreckage in between, so different bits will be obscured by different amounts of smoke and fire.

I do not want to light the bits from the pyro (it doesn't have to be photo real/or even close, going for heavily stylized result).

I reckon I will be able to figure out the slow mo but I'm not sure how to render different depth slices of the pyro.

 

Thanks in advance for any help

 

Nick

PS: Want to use Redshift

Edited April 2, 2021 by amaviztime

[Vinz]

Dear Nick, Maybe 'Volume_Slice Sop' can help. You can visualize heat and or density attributes anywhere across the volume (I have no experience rendering that one though).

Another idea could be to play with the simulation box limits/size (the pink box) by setting the fire to not collide against it and let the box limit to clip it where you want.

[ryew]

A quick and dirty hack is also to just adjust your camera near and far clipping planes to crop out sections in depth for rendering only a specific region.

Alternatively, use the VDB combine node to clip the cached volume to the intersection with a VDB box you have created.

[5DNick]

Thanks guys. Thanks for the help.

[olivetty]

I'm doing something similair at the moment and was wondering what you ended up doing on your part? How did you solve the slicing and rendering bit?

[5DNick]

I abandoned it due to artistic considerations, but I imagine ryew's second suggestion would be best.

"use the VDB combine node to clip the cached volume to the intersection with a VDB box you have created".

 

Hope it works well.

[paranoidx]

or you can use a Volume VOP then sampler that volume with half of the dimension you want to slice then multiply all back to @density. You will get half or what ever slice angle.