I changed tempo at end of my project to make a ritardando ending. After the midi files are done, I started to change them to waves format for mixing. all the tracks waves pictures are fine except of their ending exactly the place I changed the tempo. there is no picture in that specific measures I changed the tempo. I can hear them bout no picture. I used to do the same thing with X3 and no problem but with Platinum it causes this issue.
any help will be greatly appreciated
 

Ok now i could replicate the issue. I just play one midi track and change the tempo during the instrument is playing and bounce to track. Yes again the part I changed the tempo doesn't show the waves picture. :(
So it means it is a bug and needs to fix.

How many tempo changes end up getting entered? Are you drawing them in the tempo view? Wave-picture drawing issues can occur where there is too high a density of tempo changes. When drawing tempo changes, it's easy to enter too many and this won't necessarily make the ritard any "smoother". Musically, there is no purpose in having tempo changes between note events; all transitional tempo changes can and should be distilled down to a single tempo change for each note interval.
 
 

I have the same issue when I have accelerando/decelerando passages. I thought this was intended behavior, since the waveforms would be stretched in weird ways.
 
Trying to calculate a single tempo change per note for accel/decel is not practical.
 

brundlefly
Wave-picture drawing issues can occur where there is too high a density of tempo changes.
 

I've seen this just yesterday but had only 2 tempo changes in the entire song (half time and back to normal) ... when starting to record a take after the tempo change, the waveform preview was only half length (due to double tempo) - but this is just a graphic/drawing issue as all the recording were captured properly

That screenshot is a perfect example of what I'm talking about. It appears there are a dozen or more tempo changes per measure in places. Unless some instrument is playing continuous 8th triplets or 16ths through that passage, it isn't necessary to have so many changes.
 
But even with fewer changes, any notes that sustain across tempo changes will tend to get drawn a little strangely because in SONAR M:B:T grid is the fixed time reference, and the Now cursor speeds up or slows down with tempo changes. This means the visual length of a wave has to morph to fit the grid. This wouldn't happen if absolute time were the visual reference and measures changed length with tempo. I've often though SONAR should have a display mode that works this way. It's more logical in many ways.
 
 

Thought I was seeing things the first time I encountered the disappearing waveform behavior.
 
In case the OP doesn't already know:  To visualize the waveform for editing, zoom in on the section of the track with the tempo changes and the waveform will magically appear.
 

brundlefly
This wouldn't happen if absolute time were the visual reference and measures changed length with tempo. I've often though SONAR should have a display mode that works this way. It's more logical in many ways.

A couple of other DAWs (S1, Rpr) do scale the measure length instead of scaling the waveform.  Can't say whether one is better than the other.
 
Ron
 
 

So it means there is no way if we want to change the tempo gradually and don't have the issue???????
Then how we can make accelerando/decelerando without this problem. This is one of the most important part of song writing specially classic music. 
Maybe we can ask cakewalk to do something for the next update :)
Thanks for more advice.

As Ron said, zoom in a little, and the waveform should appear more clearly. And I repeat my advice to only place tempo changes at note starts; this should help a lot.
 
As you've said yourself, it's just a display issue, anyway. It's only relatively recently in the history of music that composers could see the waveforms of the music they're composing, and somehow many ritards have been successfully written, played and recorded. Yes, I'm being sarcastic; all those questions marks made me do it. 
 
But, seriously, I think you're making a mountain out of a molehill; in the grand scheme of things, this shouldn't significantly be impacting your ability to write and record orchestral music.
 
I'll add that I think a better way to create a ritard/accel is to record a part (or just a reference track) in real time and then use Set Measure/Beat at Now to tell SONAR where the beats fall. You'll get a much more realistic result.

brundlefly
As Ron said, zoom in a little, and the waveform should appear more clearly. And I repeat my advice to only place tempo changes at note starts; this should help a lot.
 
As you've said yourself, it's just a display issue, anyway. It's only relatively recently in the history of music that composers could see the waveforms of the music they're composing, and somehow many ritards have been successfully written, played and recorded. Yes, I'm being sarcastic; all those questions marks made me do it. 
 
But, seriously, I think you're making a mountain out of a molehill; in the grand scheme of things, this shouldn't significantly be impacting your ability to write and record orchestral music.
 
I'll add that I think a better way to create a ritard/accel is to record a part (or just a reference track) in real time and then use Set Measure/Beat at Now to tell SONAR where the beats fall. You'll get a much more realistic result.

Thanks for your replay but i don't make a mountain out of....,I composed the music and now the singer wants to mix it down in another studio out of the country . So what did you do if you wanted export all the tracks for another studio which doesn't work with sonar? 
It is part a professional job to export the tracks properly.and for sure if i knew it i wouldn't ask :)
by the way you mentioned to record in the real time. do you mean record the wave in real time or midi? I recorded all the midis in real time and asked sonar after all to change the time. Could you please give me more info or if there is any link or something like that, i can see?
Thanks in advance