Error in documentation? Transformation of instance build inputs

Gaming and Visualization Technologies Visualization OptiX
1

Hi,

I found that there are two opposite definition of instance build input transformation.

In the instance build inputs document, the transformation is defined as A static 3x4 row-major object-to-world matrix transform
https://raytracing-docs.nvidia.com/optix7/guide/index.html#acceleration_structures#instance-build-inputs

However, the API documentation of OptixInstance (https://raytracing-docs.nvidia.com/optix7/api/html/struct_optix_instance.html) and header file of OptixInstance says it is defined as affine world-to-object transformation as 3x4 matrix in row-major layout.

I tested some cases and it seems like the transformation is defined as object-to-world transformation.

Which one is right? or Am I missing something?

2

Hi @wonjunlee.0729, the header file has a mistake. You are correct that the matrix is object-to-world.

–
David.