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View Full Version : Reliable tools for converting to triangles and reducing polygon count



wtdedula
01-31-2012, 02:11 PM
Hello All;
I have been posting a series of messages (and getting various responses) on developing 3-D content out of Lightwave for usage in a 3-D interactive game simulation. I have been trying a lot of things and have been learning a lot but I still need some advice.

I am trying to create a robotic builder concept that can be used to build components on a future lunar base. Our developer wants me to try to keep the model down to 5,000 polygons (Though someone corrected me and said that was triangles and now I think he's right). Yes I know that most well-to-do folks have super smokin computers that can handle much more but our primary target is schools who typically don't have very good computers - that's the reason for the low triangle count/model.

I have been able to get the model down to 5,500 polygons but when I reduce the polygon count with Reduce Polys +, and set the reduction to 80%, the parts of the model that don't have much geometry look very odd and really bad.

Is there an acceptable solution to converting a polygonal model into a low triangle mesh ? If I just triangulate without reducing the polygon count, the model looks nice but is way above our triangle count limit.

A few folks suggested using a retopology tool and I checked them out but am unsure if that will give me what I want. Can anyone advise if a retopology tool such as Topogun, Push, or easyretopology would help and if money was no object, which one offers the most features and control ?

For those of you who didn't see my earlier postings, I am attaching a screenshot of the model I am currently trying to reduce and convert to triangles with many more to come after this. The large image is the good looking model in quads and the smaller image is my attempt to convert ot to Trangles and reduce it. See attached below.

Tim

Sarford
02-01-2012, 01:39 AM
As far as I know it you'll have to do it by hand. Building low-poly models is an art form.
There are polygon reducing algorithms and some take into account edge sharpness etc, but none of them 'know' what they are reducing and most of the time give unwanted results.

By looking at your model, you will have to start to cut corners (hehe :D) if you wanna stay within your budget. For instance, you can take that bevel off the wheels, that will save you 240 triangles. You can take out the axle from the wheels as you don't see that at all, that will save some. The cylinder shape halfway the long arm is quite high poly compared to the rest, etc.

In short, remove or reduce polygons everywhere possible without compromising the overall shape or the detail too much. Not a lot of work, and better than to rely on some algorithm.

Btw, as your model is already relative low poly I don't think retopologising is going to do you any good, and tools like Topogun don't have any automatic retopo feature (3D coat does however). You still have to draw every poly. The main advantage is that those stick to the surface of the high poly object so you only have to worry about the polygon flow and count and the program takes care of the shape.

Danner
02-01-2012, 03:13 AM
You should have posted to the original thread. The bad news are.. Automatic reduction works well for organic models, mechanical models usually have to be remade with the limits in mind.

Your model is complex, it will be missing a lot of detail to get it to the target poly count, there is no way around that.

For details like polygons in the middle of other polygons (like the rotational axis on the legs knees and above the wheels or even the things that look like eyes) use textures instead of geometry.

wtdedula
02-01-2012, 05:19 AM
Sarford and Danner - I want to thank you very much for your very helpful feedback. This helps tremendously to know how best to proceed and gives me some ideas and things to try. If anyone else has any additional thoughts and ideas, I'd still love to hear them. I've learned so much from this forum.

Tim