# Mai Ao

MaiAo

LOCATION
ウェブサイト

Not Specified

## チュートリアル

Node Reference
SideFX Labs | Volume Adjust Look

## My Talks

Houdini HIVE
H19 Real-Time Pyro Workflows - Chasing Photorealism
Houdini HIVE
SideFX Labs 2021-2022 | Servicing Next-Gen Development
Tech Talk
The Matrix Awakens: Generate a World
Tech Talk
The Magic of Houdini
Houdini HIVE
Recreating Heritage Sites
Houdini HIVE
You Asked Me to Make the Flipbook Exporter Better. Let's Do It.

## Recent Forum Posts

#### Matrix multiplication confusion2023年5月24日18:07

A vector to rotate
```vector v = @P;
```
Rotates 120 degrees about {1, 1, 1}
```matrix3 A = {{0, 1, 0}, {0, 0, 1}, {1, 0, 0}};
```
Rotates -90 degrees about {1, 0, 0}
```matrix3 B = {{1, 0, 0}, {0, 0, -1}, {0, 1, 0}};
```

If you want to rotate the vector by 120 and then -90...

The convention is to write this from right to left, meaning the vector is transformed by A and then by B.
`v = B * A * v;`
You would expect to have: BAv == (BA)v == B(Av). But in VEX: BAv == (BA)v != B(Av).

VEX actually write this from left to right.
```v = v * A * B;
```
So you actually have: vAB == v(AB) == (vA)B.

Surprisingly, VEX does not care about the order when it is a multiplication between a vector and a matrix.
Effectively: vAB == v(AB) == (vA)B == (Av)B == AvB.

#### Houdini 19 Mapbox not functioning2023年4月18日10:08

monci
...

@MaiAo Any ideas of using 1024 or higher resolution for heightmap?

Mapbox confirmed that their new API only support up to 512 now. We can look into whether there is a good way to upres it. Overall fix for the bug ETA early next week if not sooner.

#### Houdini 19 Mapbox not functioning2023年4月11日10:19

swSharkBoy_02's findings are correct. Mapbox changed their API for elevation/height map access. I'm talking to Mapbox devs about this issue. We will update the tool as soon as we find a satisfactory fix.

To further clarify, the error message generated by our Mapbox node is due to missing height map, which in turn was due to height map download links stopped working.