A word about my 2.5d trees...

[tomsdesk]

...explode!

Playing with Twilight I've noticed several of my previous trees were doing strange things, but in full model context the scope wasn't obvious. (Others I believe have had the same problem in other render apps...?) So doing the first render of the first tree of the new set of PR image trees hit me pretty hard:

tn_!oak-image.jpg (106.32 KiB) Viewed 11387 times

But exploding the image (only the image inside the leaf-bunch component...which are grouped together inside the whole tree component), then hidding the four edges of course, solves the problem:

!oak-explode.jpg (115.26 KiB) Viewed 11388 times

For some reason, doing this will also speed up the AA phase of rendering (4 times faster on this little image)...but it does add 30+ faces and 120+ edges per tree to your model, so only you know when it is time to explode the leaf-bunch image.

I've also noticed, but haven't yet proven with certainty, that creating the original tree in SU7 alleviates the problem without exploding the image...? Anyway, I will create future tree sets in SU7 (saved back to SU6 I suppose) and with Twilight am now able to verify the rendering results of my product, thank you very much.

[Gaieus]

This is interesting Tom, as yesterday I was playing about with lighting with fire and I had a flame image (got it and the whole idea here, on the TL Forums and still owe a big thank you) so I had the flame image and duplicated it by moving a copy behind it > scaled by -1 (i.e. mirrored) horizontally and scaled up a bit (I can't attach the skp file as it exceeds the file size limit but can post to anyone interested).

Now while this image entity was correctly in place in SU (see SU export), it somehow rendered somewhere way below the "fireplace" (actually a tripod). Somehow as if it were mirrored vertically, too, but not about its center (as I did above) but about its opposite (lower) point (see attached render - material is Solo's dirty metal - thanks - and as it has linked bump and specular map, it may not render exactly the same way as in the picture is someone downloads it).

Then I exploded the image entity, hid the four edges (although you don't need to do this for rendering) and everything was just fine.

[Ecuadorian]

In Twilight, unexploded images render with full 0-255 alpha transparency, and thus are a lot slower to render. Textures and exploded images render with "clipmapping", meaning there are parts 100% visible and parts 0% visible, and no intermediate points. These render very fast.

[Gaieus]

That's good to know for further work, Miguel, thanks!

[Chris]

Thanks Tom!! I appreciate the update.

SketchUp treats images differently from normal geometry. Why, I don't know, because it's completely unnecessary. Exploded images are just a single rectangle with a texture applied, so why the complexity built on top... who knows. What I do know is that it makes dealing with images complicated and leaves them prone to a lot of positioning problems. So exploding images is always a good suggestion if you are seeing position problems.

In the meantime, we are always working to solve the little mysteries, so hopefully we'll get this one figured out too!

[Fletch]

Hi Gai,

We know there's an issue, but it's not been 'nailed' yet because it's a completely unreliable 'bug' - meaning it doesn't happen all the time... please try sending this particular problem child to support at twilightrender dot com and we will see if perhaps it will be the 'key' to nailing the 'bug'.

[Gaieus]

OK, I will. I will also write down in details what step I did.