To add a bit to what others are saying. Mesh mixer is sometimes a great tool for some of this. Source: 9 months ago

Ah right. If you can't get the source file, you could try smoothing them out in meshmixer. Source: 11 months ago

The quickest fix I know is to use the free meshmixer. Source: about 1 year ago

There are programs such as Meshmixer specifically intended to do that, others such as Blender which can do a good job (but beware of missing surfaces or inside-out triangles) and some CAD programs such as Fusion 360 which have the ability to convert meshes. Even Tinkercad can make some changes. It's always better to get a CAD file in a common interchange format such as a STP (STEP) file if you can, though. Source: over 1 year ago

Meshmixer seems to be no longer in developement, with their integration of similar features with fusion360 according to their site https://meshmixer.com/. Source: over 1 year ago

Autodesk Viewer is what you’re looking for. Source: about 1 year ago

Autodesk Viewer is a powerful and versatile online tool that allows users to view, measure, and mark up 2D and 3D design files. Whether you're an architect, engineer, or construction professional, Autodesk Viewer can help you streamline your workflows and make informed decisions about your projects. Source: over 1 year ago

I use Autodesk viewer to share preliminary 3ds at work, you'll have to sign up to upload and use it but once you have the link afterp you upload you can share it with anyone, there is a time limit of 30 days for uploads, but can be manually extended another 31 days https://viewer.autodesk.com/. Source: over 1 year ago

You can measure what you need from the 3D model provided on the product page here: Https://lian-li.com/product/o11-dynamic-evo/#:~:text=top%20accessible%20IOs.-,Downloads,-O11D%20EVO%20Manual You can use this online software to view it: https://viewer.autodesk.com/. Source: almost 2 years ago

I recommend you to upload the model toAutodesk Viewer, then share the link. Source: almost 2 years ago