python -m venv venv
If you are using Linux (Ubuntu)
source venv/bin/activate
If you are using Windows
venv\Scripts\activate
pip install torch==1.9.0+cu111 torchvision==0.10.0+cu111 torchaudio==0.9.0 -f https://download.pytorch.org/whl/torch_stable.html
pip install mmcv-full -f https://download.openmmlab.com/mmcv/dist/cu111/torch1.9/index.html
pip install scipy
git clone https://github.com/jrcastropy/mmdetection.git