On Tue, 14 Mar 2000 07:15:06 -0500, Chris Huff
<chr### [at] yahoocom> wrote:

>In article <9=XNONfHim9haARAc396blnM8yDn@4ax.com>, Glen Berry 
><7no### [at] ezwvcom> wrote:
>
>> Perhaps the parser could scan for such interactive features first, and
>> let the user know that they need to watch the screen to add input to
>> the scene data. If no interactive features were found in the scene
>> files, then the parser could even issue a statement to that effect,
>> and proceed to render the scene while you went out for the weekend.
>
>There is still the problem of having to wait for the dialog/prompt to 
>pop up while the scene is parsing. I have had scenes that took 45 
>minutes to parse.

I can't imagine how it would possibly take anything approaching 45
minutes to scan for the appearance of a few interactive keywords,
requiring user data input,  in a POV scene file. If some are found,
the values would be entered at that time, before the "real" parsing
would begin. There should be no such thing as sitting in front of your
monitor for 45 minutes waiting to enter data into a scene that is
parsing.

>> It should also be possible to "remember" the values entered during the
>> last rendering of an interactive scene file, and use them for
>> "default" values when queried by the current interactive rendering.
>> Let's say you have ten seconds to change the default value, or the
>> scene continues parsing with the default value. Hitting the "return"
>> key would simply accept the default value as-is, and avoid the ten
>> second delay. In order to store the previous query values, POV's
>> text-file output capabilities can be put to use in a method similar to
>> Nathan's use of an external file for storing photon or radiosity data
>> for subsequent renders.
>
>This is getting too interface-dependant. I would rather not have 
>language features depend on the interfaces of different platforms.

Are you telling me that ASCII text file reading and writing is a
highly platform-dependent operation? What about asking an end user to
interactively type a variable in response to an ASCII screen prompt,
are you saying that is also highly platform-dependent? It just so
happens that these operations are found in every basic C/C++ book I
have seen. I always thought they were considered portable.

>And what about automatic rendering? If POV is being controlled through 
>something like a web page, this kind of feature would have to be removed 
>or heavily modified.

Just because a feature might not be useful to you for every scene you
write, doesn't mean the feature shouldn't exist. Do you currently use
every keyword in POV for each scene you create? I think not.

If you have an objection to user-interactive pre-parsing, no one will
make you use it. At this point, I'm wondering if there is *any*
feature-set change I could suggest for POV-Ray and get a favorable
response from you.

>It is simple enough to make an include file with the variables you want 
>to use so you don't have to remember the names, or you can put them in 
>the main file and just use comments well. And this doesn't have the 
>complications of a user prompt.

"...complications of a user prompt"?

Some would say that a user prompt would greatly simplify some things.
One wouldn't have to remember all the names of all the variables in a
scene file that frequently needed changing. The script would prompt
you for values as it needed them. One person could write an
interactive include file and another person could run it without ever
having to look inside the source code to find all the variables that
need to be changed to suit their particular needs. There would be no
more searching through convoluted code, possibly scattered through
several include files.

You seem to have the mind set that in the future all scripts would be
interactive and you wouldn't be able to overide that interactivity. No
one is proposing a scenario like that. If my earlier suggestion for a
default value that is used after time-out period doesn't suit you, it
would also be possible for POV to simply ask if you wanted to
pre-parse the scene in interactive mode, or simply use the last
user-entered values. If no user-entered values existed, default values
could be written into the script. This would be a global rejection of
user-input as compared to the earlier example of line-by-line
bypassing of prompts. Furthermore, both the global and the
line-by-line rejection options could be incorporated into POV-Ray for
the most flexibility.

Later,
Glen Berry

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