I loaded a high-poly vehicle model in .obj format that "weighs" about 531000 kb into Poser. Loading took a while and afterwards Poser drags as if I loaded the real vehicle. The low-poly version (53000 kb) which I tested first was not entirely satisfactory, even after applying smoothing.

Is there a way to reduce the weight of this model without it visibly losing its quality ?

Some modeling applications have a polygon reduction feature, but Poser doesn't have anything like that built in.

Google is good

Drop it into a modelling app.  If it's triangulated it's dead easy to reduce the poly count without sacrificing quality.  It's just very, very tedious.

Other than that, you'll have to play around in a modelling app anyhow, which would amount to almost remaking the model from scratch. 

Quote -  If it's triangulated it's dead easy to reduce the poly count without sacrificing quality.  

That really depends on the modeling app - not all of them are smart enough to handle that without trashing the UV map and screwing up textures.  And oops, I also didn't mention this will trash morphs in the model, assuming there are any.

What everybody said.

The only program that I know of that will allow you to tweak and reduce the poly count without trashing the uvs is Silo and it's not free ;). That and I have no idea how good a  job it does with that. Everything else that I'm aware of will destroy the uvs. And even if done in Silo, any morphs would not work as pjz99 has pointed out.

Laurie

are you saying the obj file is 531 mb or am I reading that wrong ?

an obj file can have lots of whitespace , a better indictor might be number of vertices and polygons.

Try to find double sided surfaces and delete unvisible. It destroy morphs but I think that vehicle is rather rigged or magnetized.

You might want to take a look at 'Atangeo Balancer'. It preserves UV's and can also preserve edge counts so that grouping welds still function on Poser figures.

There is a demo and a free version if you want to try it.  I used it some time ago and was very pleased with the quality of it.

Meanwhile the creator of the model and I have been testing various sizes and formats of the model. All high or low poly untill recently. Then he sent me a mid-poly Collada format (.dae) model. As it turns out this model delivers the best compromise between quality and performance in Poser. Remains to be tested how other mid-poly formats perform in Poser.