OpenVDB won't load as a sequence

[cole-n]

Working in 3DS Max.

Using FumeFX.

I've output a OpenVDB sequence for an explosion and am trying to use an Arnold Standard Volume to render it in.

For some reason it makes me reload the explosion for each frame. In other words rather than just hitting render and have it render the sequence the explosion will stay on the first frame unless I go and load in the next frame.

Obviously this is not ideal.

I read a similar issue here: https://answers.arnoldrenderer.com/questions/2515/mtoa-openvdb-sequence-file-problem.html

However when I tried to use a naming convention like explosion_sim.###.vdb it just came out as explosion_sim.###_0123.vdb - completely defeating the point.

I've also tried loading in the sequence like explosion_sim.###.vdb but 3DS Max just returns with an error message that it isn't a valid file name.

I then found another source that said to start naming it from 0, so explosion_sim_0000.vdb.

This prompted a dialogue box asking if I wanted to load it as an animation which I said yes to, then the explosion no longer appeared in the render.

I played about with the Animation Support options in the Volume Object modifying options but still no luck.

Any help would be greatly appreciated, I'm losing my mind here.

[madsd · Accepted solution]

Start frame and offset in the vdb loader needs tweaking.

You are correct, 4 digits needed. start from 0000.
Ive done this for years sourcing vdb sequences from Houdini.

Once you enable animation support, fix the offset and move timeline around, watch for data change, meaning the vdb cage moving.

[cole-n]

Hi thanks for the reply.

Just to make sure I'm getting this...

Once you load in the sequence then you scroll through the frame offset (in the Animation Support section) until the vdb cage reappears?

My sim starts on frame 0123 so would that mean I'd need to rename the frames to 0000 or will the offset start it at the right time?

[madsd]

I would do like this.
Then offset the start to 123.

[cole-n]

In case anyone was wondering about the offset, I found out - after renaming my sequence using a free Bulk Renaming Utility that was easy to install - that in my case I had to use the animation support window and offset the frames by minus 123 frames (-123).

If I just typed this value in, for some reason it lost the minus symbol every time, but if you clicked and dragged the values down to minus it would retain the negative value.

Long story short : essentially load in frame 0000, confirm its a sequence, and then scroll down and offset the sequence -123 frames and it played at the correct time.