Ray trace objects On/Off

[AndyWelder]

Below are some samples of partial renders; part of them with "Ray trace objects" on.
What puzzles me is what's happening to the vegetation. I'd expect to see more detail with RT On but the opposite is true: Leafs(needles) disappear? Render times are almost twice as long  and that's puzzling me too because if I check RT for the atmosphere render times are shorter.
Didn't have enough caffeine in my blood when I wrote the last sentence: Render times are shorter with RT on.
Could someone explain what's going on, please?

[Henry Blewer]

I did some render tests for one of Walli's plants. I found the plant did not render correctly using RT objects on. This may be a bug. I thought it was something with Walli's plant.

[TheBadger]

I just ran into this as well I think. I have a big gap in one of my renders where I know I have filled the area with trees. lower quality renders did not have this problem, but when I made a huge render this happened. Would like to understand the problem as well.

[TheBadger]

Im starting to think that this could be a memory related problem. Im my case I used FrankB's spruce and pine, these trees have large file sizes. When I opened my TG file of the image above and checked my activity monitor I saw that I was going beyond my 8GB of real memory into virt mem. Im no expert in anything we talk about in these threads but I think there is a connection. Can someone confirm, somehow?

[Tangled-Universe]

Hi Andy,

The comparison between RT On and Off is exactly how I would expect it.

Visual "shrinking" of plants is because the RT renderer is more accurate and more capable of rendering subpixel detail at lower AA settings.
The more inaccurate rasterized renderer tends to visually "blow up" fine details like leafs and such.
So I think you're mistaken this visual difference as the RT On situation as inferior.

Cheers,
Martin

[Dune]

I don't see the problem in your render, Badger. If you would hit seed, the 'empty' spaces would likely be somewhere else. Or in that particular area the slope was just too steep (if you set slope restrictions). The spreading is never completely evened out in the basic settings.

[AndyWelder]

@ Martin:

...because the RT renderer is more accurate and more capable of rendering subpixel detail at lower AA settings.

Maybe there's too much blood in my caffeine but I don't get what you're saying there. My first response is "But these are rendered with an AA of 6!!" but I have a feeling that's I do miss your point.

The more inaccurate rasterized renderer tends to visually "blow up" fine details like leafs and such.

I get that and already was suspecting this was what happened with the purple heather. In this case I also did like the render with the RT on more because with RT off the heather did look too "fluffy".
My main concern was the disappearing of (most of) the needles in the pines render. And I still don't get that because the object/TGO files are huge and, while saving them after creation,  around 80% of the file-size went into the display of needles.They're certainly not low-poly...

[Henry Blewer]

Here are a couple of Walli's plants that I test rendered. You can see the alpha channel on the bug eaten part did not render properly with RT on.

[TheBadger]

I don't see the problem in your render, Badger. If you would hit seed, the 'empty' spaces would likely be somewhere else. Or in that particular area the slope was just too steep (if you set slope restrictions). The spreading is never completely evened out in the basic settings.

Dune you can see at the end of page 1 on this thread: http://forums.planetside.co.uk/index.php?topic=12782.0 the same image as I have above, at lower render settings the trees are there. But as you can see above, they are now gone. I thought it was a memory problem, but since that does not seem to make sense to anyone else, maybe something just got moved, or I ticked a button or deleted something without realizing it?

[AndyWelder]

Let me rephrase the question posed here: Why do object parts not show in a render though they are clearly visible in the 3D preview with " Show as wireframe" checked?

[Kadri]

I do not have these objects .  
Do the objects have displacement-bump maps?
The micro render does real displacement and is more pronounced.
Ray trace is more kind of a bump map and not so prominent.
Maybe in the micro render the object do look bigger because of the real displacement?
Just a thought guys!

[dandelO]

The wireframe preview doesn't include the alpha mapping of leaves etc. Taking that into account, you'll realise that you are only seeing the actual 'wire frame', not the final result, which cuts out areas of the mesh, making it appear smaller than your preview.

[AndyWelder]

Do the objects have displacement-bump maps?

That does not make any difference because this happens with an object fresh from the application it's created with, it happens with an object that ran through PoseRay and it happens to an object that was converted into a TGO.
This is not something that only happens to my own home-made objects, I see this behavior also with the objects from other people.

What's a micro render?

[AndyWelder]

The wireframe preview doesn't include the alpha mapping of leaves etc.

The needles don't use image maps, they're polygons (six sided, if I'm not mistaken)

[Kadri]

...
What's a micro render?

If you check "Ray trace Object" the objects will be rendered with ray tracing,if not they will be rendered with the micropolygon renderer.
http://forums.planetside.co.uk/index.php?topic=12890.msg127827#msg127827
If you search you will get more answers about this , Andy.

I have to try this.But it could be obviously the way the renderers work.
I have a feeling Matt should maybe change some settings if this is the problem really.