Hi Jim in 'Chemsfud',
Hope all's well.
Most of your questions have been answered over the years in various posts here. Searching the forums using:
http://archicadstuff.blogspot.com/
may help you find more information - since searching for "VR" will not work with the forum search, but with the google search via the link above, it will.
On your points:
1. Do not use the LW Sun object. In AC 12, the Realistic Sun is preferable. See Dwight's posts and/or book. The Sky object is not necessarily needed either, as the ambient value in the rendering window can be fine. Tracking with viewpoint works fine.
2. Blotchy colors is your compression codec settings
3. Yes, your VR pixel dimensions are important ... and the dpi never matters. Be sure not to generate too big of an image (e.g., bigger than the client's monitor). QT will display anything, so there is no need to use any kind of standard video pixel dimensions, just something that balances image size and file size. 1200 x 800 is way too big IMHO unless the client definitely wants a really big image and has a 1200+ pixel wide monitor. 1024 x 768 should be big enough (or whatever - consider using a standard 4:3 or 16:9 ratio as people are accustomed to seeing TV images in that ratio). CERTAINLY use something small - like 640 x 480 or 320 x 240 to generate a test object first to verify your settings/etc ... it will be dramatically faster than the big render which should be done once you find everything is otherwise perfect.
4. Yes, a different codec will affect the color and image appearance dramatically. No compression will be really huge. Neither a VR Object nor a VR Panorama is really a movie. A QT panorama is a single special image and a QT VR is a sequence of individual images. Use JPEG compression for each of these things. (Cinepak is NOT "recommended" ... it just happens to be the bizarre default.) With JPEG selected, one notch less than highest quality is probably a reasonable setting. Be sure you select millions or millions+ for colors before generating the object. Do not check 'dithering' for the jpeg options, nor fast streaming (only appropriate for a single image). You will be surprised at how small the final file will be.
5. This has been talked about many times by Dwight. That is how it works... top settings use a single core. So, don't use top settings. Once notch less is probably good enough. It'll be so much faster - especially if you do a test object with a reasonable size image and fewer longitude/latitudes to check your results first.
The sun followed the viewpoint just fine for me in my tests just now.
Consider not using a solid blue/internal background. The LW background offers a gradient between an 'upper' and a 'lower' color - for example blue fading to white or whatever.
Again, the reason you could not find other posts for most things (other than the single core with best LW settings) is that the forum search will not search on any terms with fewer than 3 characters (e.g. "VR").... so use the link at the top of this post when searching. But, I think I have your questions covered.
Good luck with it!
Cheers,
Karl
One of the forum moderators
AC 28 USA and earlier • macOS Sonoma 14.7.1, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB