I'll give $10 to the best explanation

You're not going to get any useful responses from this because your problem specification is woefully incomplete.

"a simple 3d software for windows or online-based".

That's like saying, "I need to drive somewhere. I'll pay $10 for the person who can suggest the best way to go." Do you need to go across the street, across town, or across the country? Do you have any particular physical needs? Why can't you fly?

Here are a few questions that come to mind that need to be addressed:

Is your 3d software interactive, like a game? Does it need to show videos? Still images? Does it need to do 3d surface rendering? Wireframe modelling? If so, how fast? At what resolution? Do you need 360 degree tilt/pan/zoom/roll? Does it need to be saved or retrieved from a database? Is there data that needs to be interpreted to display whatever it's displaying? If so, where does the data come from? Maybe it's just a graph; if so, what are the 3d axes?

BTW, if you ask a person who only knows how to write poetry in Chinese for several options on what's the best approach to use for writing your classic Italian opera, would it surprize you if all of the suggestions said to write it in Chinese?

(Also, anybody who's stupid enough to suggest writing a Flash app in C# should not be trusted for ANY advice! Flash is programmed in one of two platforms: ActionScript and Flex. You package it for use on desktops in AIR.)

The other suggestions are ok if you plan to have this guy working with you for quite a while.

Since this guy is apparently a C# bigot (or, that's the only programming language he knows), he should at least be suggesting you go with Silverlight. However, Silverlight only runs in a small fraction of computers today, while Flash runs in over 99%.

Using C# will also significantly increase your customer support overhead because of all the problems that arise from people using the wrong .NET framework.

Thanks for that Sagesound, I can't reveal specifics of the project for obvious reasons, but it involves something similar to inserting a jpg picture and converting it into a 3d shape and be able to export a 3d animation in flash format. The software does not have be a flash application, but rather be able to export to flash format.

So...

1. C#

2. C#

or

3. openGL?

Well, realistically the language doesn't matter. You can do whatever you want in C#, C++, VB, .NET, heck...probably even SmallTalk.

More important is...are the graphics libraries accessible? And what do you want to achieve...?

Sounds like your programmer is familiar with C Sharp. Great. So...can he do what you want?

Yes/No?

Steve

Web based program will get you the most exposure and advertising possibilities. I have found a few sites in the past that already offer this sort of thing. One nice feature that I liked from them was the ability to import my own picture and use the tools to make my 3D image with motion, camera and lighting controls. One feature missing was the ability to add textures and various color options for the object. I think you would have a winner if you added these features and a really good tutorial on how to use the software via video.

Again my vote would be for an online software if you can make one.

I got lost at the $10 point :-)

Sagesound - have you considered making this a SaaS (Software as a Service) app instead of a desktop app? I.E basically making this a website that people upload their image to, it gets converted, and then gets sent back to the user?

That way you only have one instance to maintain and can control maintenance/updates/access. Supporting a desktop app requires a lot of resources to do it right.

Valuations today, while in the toilet because of the economy, also places a higher premium on SaaS applications (upwards of 7x revenues) vs at most 2x revenues for an installed app.

Food for thought.

Also I know C and C++ cold - but am not a graphics or flash guy, so can't really comment on your approach. I would suggest having a good architect do the design and get testing and QA involved in the beginning. Design and code reviews, while they may seem to add time/costs to a project - really cut down on the cost later in the development cycle.

Also another item to consider is SaaS really lends itself to the current Agile development philosophy. Stand alone apps can be forced into it (IMHO) but doesn't fit as well as a SaaS app.

Good luck,
best,
--Jack