Week 7

Final Result:

Things to work on this week:

• Get pyro to react more to the car going from idle to driving (blow out more / be puffier)

• Fix lighting (sharp line separating light and dark areas of smoke)

5/15

I put my pyro on the render farm, but didn't know if it would be done in time so I locally rendered it as well. The local render was done with no added samples and at a lower resolution. In the final video (above) I just have the local render. Below are some tests I'm doing in Nuke to see what works best. I realized after I got the render from the farm back that I never uploaded the vdb so it is slightly different than the local render. Also, I need to expand the matte objects in Houdini so I don't have to do any roto work in Nuke near the tailpipes.

This is the render farm version by itself.

This is the local render and the render farm render merged together.

5/14

My first approach at getting the smoke to accelerate and become puffier when the car takes off was by putting keyframes on the velocity. The velocity was already set to 250, so right before the car takes off I increased it to 500.

I didn't see much of a difference so I added a wind force. The wind force didn't do much either and I figured it was because I had only deleted the top inner circle of the collision object. I deleted the bottom so that the wind force could pass through. It wasn't until I went back to my pyro setup that I realized that the collision object wasn't animated. I copied the keyframes from the emitters and put them on the collision geometry and that got rid of the big puff that happens once the pyro goes under the collision object.

After getting that fixed, I added keyframes to the disturbance and shredding so it would increase when the car was about to take off. Unfortunately, I still didn't see the difference I wanted. I figured maybe if I put the keyframes earlier I would be able to see the change earlier and more dramatic since it wasn't taking off at the same time.

Keyframes Later

Keyframes Earlier

I still wasn't seeing the difference I needed, but these flipbooks were taking 40 minutes and I didn't know what else to try. So it was time to move onto the lighting problem.

Ever since I lit the pyro, I've been getting sharp lines splitting where the light and shadows were. I turned on all the lights individually to figure out which one was the problem. It was the key light that was causing the sharp line. Turns out I had turned all the lights from distant to sun except the key light.

5/10

One of the things I've struggled with the most during this project was getting the Maya animation to translate in Houdini. Simply parenting or even copy and pasting the keyframes didn't translate right in Houdini. There was always an issue with the pyro not following the car perfectly. The only solution I found for that was hand key-framing it myself.

This is how the emitters followed the car when I used the keyframes that came in from Maya. They are supposed to be inside the tailpipe.