@Musicvid

Thanks but they are not staying as temp, they don't get created to use in any way, i don't adjust anything, it is as it is in the video, that video is totally unedited capture of the screen in real time, i don't click anything, as soon as prerendering is finished they disappear as if never created, instantly deleted or not fully inplaced, Before this issue the files were there & the part of the track would play clearly as if it was playing a single unedited, unaffected clip, Clean prerendered files removed them, 

I'm not sure if you are talking about File PreRender or RAM PreRender.

If they are File PreRender, the temp files are stored somewhere, as long as it is a legitimate path.

If they are RAM PreRender, they of course are stored in memory, not as a file, and to be created, a sufficient amount of preview RAM must be already allocated in Preferences.

A Forum Search will lead you to more in-depth discussion, and good luck.

@Musicvid Thanks, yep i understand PC's quite well, RAM etc. 👍 it's these software things that do my head in 🤦‍♂️😂

It's called Selectively Prerender Video in the Tools option tab at the top of the screen, or highlight the area you want rendered in blue with the selection tool, then right click on the blue bar that runs across the top of the timeline to get the same option, or highlight the area then click Shift+M, it renders a video in whatever format you choose, it is in a way a temporary file for the program/timeline/preview to use as a source to help it run/preview that bit smother but it is a solid permanent MP4 (or whatever you choose) file, of coarse if you then alter the timeline that rendered source file won't match so is no good, but it still stays wherever it was rendered to until you click Clean Up Prerendered Video, I've done it loads of times because my PC sometimes won't play the complicated transitions, or at least it didn't used to, i think Vegas changed something, but Boris Particle Illusions don't play well on the timeline because of their complicity but Prerendering makes them work ,

Prerendering will work & place that media file in the folder if i set it to Video for Windows which is an Avi, just not with any of the (NVENC) MP4 i normally use & are the fastest rendering out, It will however render out to a folder in the regular Render As option,

Use a Vegas native software encoder for Selective Prerender, not a hardware encoder.

The XDCAM EX encoder is recommended, and has been as long as I've been here.

Suggest you download a trial copy of Happy Otter Scripts if you want to explore more options. You're looking for something like Kwik Proxy.

Thanks I've changed the Prerender settings to the one above the (NVENC) i chose,

which is Internet HD 1080p 29.97 fps, i've renamed it & saved as a custom with (prerender) added to the name,

Audio is still switched on but these files as i've read don't inc audio, this works fine, it max's out the CPU @ 97% but any of these that use the Mainconcept encoder do, that's why i prefer the (NVENC) they're twice as quick & a lot more CPU friendly, it's ok tho, these Selective Prerenders are brief anyway & this does the job.

Maybe tho this was the setting it should've been on & i was just being a dick, misremembering which one i was using but i'm going to leave this post in case someone else comes up with something or just needs it 🤷‍♂️

Keep well Mr @Musicvid & thanks 😊👍

Feel free to mark one of the replies as The Solution, if you wish.

It's a known bug that selectively prerender with NVENC or QSV supported Magix AVC/HEVC rendertemplates doesn't work. The Vegasteam is also aware of it.

@Musicvid @3POINT Thanks 👍 It would be nice if the (NVENC) would work but that's no prob, because people have so many different graphics cards or encoders, maybe Vegas needs a fixed, (Mainconcept), to work this process, 🤷‍♂️👍

Try XDCAM (with same framerate) instead, XDCAM is also rendered quite fast. The generated (temporary) files are only bigger. The aim is just to get quickly a smooth preview of a complex part of the timeline. (XDCAM is also used by Vegas for generating proxies).

@3POINT Thanks, i'll have a look 👍 Yep that's what i use it to help with the preview, I've used Magix Edit Pro for 16yrs, there's a prerender option on there & a lot of Vegas's stuff is similar but different, if that makes sense 😂🤦‍♂️🙈👍 Vegas has a lot more to it tho & so is a bit more complicated but that's why i bought it, I'll work it out, just need to learn a few new tricks, 👍👍

Had a look before i pressed Comment 😉...

24, 25, 50 & 60 fps but i changed it to 29.97 which it gives in the dropdown box Customize Template,

It works fine, I tried it against the Magic AVC/AAC. The XDCAM is partially quicker but a bigger file size because the Data rate on the exported MP4 is 23011kbs apposed to 12168kbs of Magix, that's no prob & it'll do it's job,

I'll have a play & see, but nice to know there's a choice n it's good to learn 👍👍