LPub3D - POV-Ray rendering quality

[Kevin]

Trevor,

As you are aware, I've been working on trying to improve the quality of the POV-Ray rendering in LPub3D.  The first step was to implement customized lighting.  That resulted in a major improvement, but I was still running into an issue that I felt needed to be fixed: many images had dark gray artifacts on curved surfaces that I couldn't get rid of simply by changing the light definitions.

I think I have finally figured out source of the problem.

When LPub3D invokes L3P, it specifies a camera angle (field of view) of 0.01 degrees (-ca0.01).  I assume that you work backward from there to determine the camera distance (-cg0,0,{large number}) in order to end up with a properly-sized image.  My guess is that you are using a small field of view and a long distance to minimize apparent distortion caused by different parts of the model being different distances from the camera.  I think -ca0.01 is quite a bit of overkill and is leading to the artifacts I mentioned.

I have modified my program that inserts custom lighting to also modify the -ca and -cg parameters.  I am currently using a 10-degree FOV and calculating the corrected camera distance.  I'm quite pleased with the results.  The resulting renders are much closer to the quality I get when using LDView to manually generate the POV file.

Can I suggest that you try larger FOV values to when calling L3P to improve the quality of the resulting render while still minimizing apparent distortion?  Perhaps this could be a value set by the user in Preferences.

I've also been working on a way to have LPub3D use LDView for exporting POV files.  I've had some moderate success, but it's pretty klugey.  Since I figured out the L3P issue, there is no longer the same level of urgency to pursuing this route.

Thank you.

Kevin

[Travis Cobbs]

I've also been working on a way to have LPub3D use LDView for exporting POV files.  I've had some moderate success, but it's pretty klugey.  Since I figured out the L3P issue, there is no longer the same level of urgency to pursuing this route.

The next release of LDView (which hopefully will happen in the not too distant future) will support command line POV exports. Trevor has already tested this with custom developer builds of LDView, and will support it in LPub3D once the next LDView becomes available. Having said that, I suspect it will use the same -ca and -cg settings in LDView that it currently does in L3P. Those command line options were added to LDView specifically to make it easier for people and software used to using them in L3P.

[Merlijn Wissink]

I've also been working on a way to have LPub3D use LDView for exporting POV files.  I've had some moderate success, but it's pretty klugey.  Since I figured out the L3P issue, there is no longer the same level of urgency to pursuing this route.

The next release of LDView (which hopefully will happen in the not too distant future) will support command line POV exports. Trevor has already tested this with custom developer builds of LDView, and will support it in LPub3D once the next LDView becomes available. Having said that, I suspect it will use the same -ca and -cg settings in LDView that it currently does in L3P. Those command line options were added to LDView specifically to make it easier for people and software used to using them in L3P.

I thought LDView was kind of 'abandoned'. Cool you're still working on it! 
Maybe a bit off-topic, but this reminded me: LDView doesn't handle touch-screens very well. At least the zooming is very weird. When zooming by pinching two fingers, instead of zooming in/out, it looks like its cutting away (or adding) 'layars' of the model. It's a bit difficult to explain, if you want I can make some screenshorts. 
Long story short, it's not possible to zoom using touchscreens, although it does make some cool screenshots 

I know not really a big deal (how many are using LDView on a touchscreen), but I still wanted to notify you about it.

[Travis Cobbs]

I thought LDView was kind of 'abandoned'. Cool you're still working on it! 

I did say that the last version would probably be the last version when I released it. However, I was persuaded by various people to add a few new features and do at least one more release.

Maybe a bit off-topic, but this reminded me: LDView doesn't handle touch-screens very well. At least the zooming is very weird. When zooming by pinching two fingers, instead of zooming in/out, it looks like its cutting away (or adding) 'layars' of the model. It's a bit difficult to explain, if you want I can make some screenshorts. 
Long story short, it's not possible to zoom using touchscreens, although it does make some cool screenshots 

I know not really a big deal (how many are using LDView on a touchscreen), but I still wanted to notify you about it.

That's very strange, but probably not something that will get fixed. Normally, cutaway is done by zooming in while holding down the control key, so that implies that Windows is claiming that the control key is down while you perform a pinch. That seems very odd.

[Kevin]

I thought LDView was kind of 'abandoned'. Cool you're still working on it! 

I did say that the last version would probably be the last version when I released it. However, I was persuaded by various people to add a few new features and do at least one more release.

That's great!  With LDView export coming to LPub3D, I'll have access to a lot of size/location variables not found in the L3P exports to further improve the lighting of my renders.