I just realized I never asked why…RTO+-

[TheBadger]

Hi,

I was thinking about some projects I have been dragging my feet on. Dragging my feet because I don't like having to render twice to get the look I prefer. That is, RTO on, RTO off.

What occurred to me, is that I never asked anyone why a plant model can't be created to look better with RTO off, so that displacements can be applied throughout a scene, and negating the need to render again with RTO on and then post work them in PS.

Now the general consensus is that RTO on looks better, and Im not arguing. Certainly it feels true for most plants I have seen. But Im not sure the same can be said for hard surfaces like buildings. And its definitely (imo) not true on very high polly objects with an additional displacement map used for fine details, including plants.

So my question is, rather than asking about Displacement for RTO on, what can be done in the modeling process to create with RTO off in mind? OR to put it another way, what should be done to a model to make the best of TRO off?.. Clear?

It may help to better define the issue of RTO off on plants, and specifically on populations of plants. Because for the most part this part of the topic has been really only discussed in terms of preference and aesthetics. But if a noob is reading this he/she will likely have no idea what Im talking about. Im just not the person to do it .

And in the same line of thinking, it seems to me most plants shown around here are from Walli. So if your reading this Walli, please chime in.

Hope Im making some sense here. I would just like to overcome some issues without having to wait 2 years for a tech fix.

Cheers.

[reck]

I would just like to overcome some issues without having to wait 2 years for a tech fix.

Cheers.

I really hope it's not going to take years to get this fixed. Hopefully allowing displacements on imported objects with Raytracing is very high on the list

[TheBadger]

They have said that it high on the list. And matt said something about a year or two.

Any Ideas? Maybe its just not realistic to try a work around?

[jo]

Hi Badger,

There's a pretty simple workaround. Use high poly objects with extra detail for RTO on. Think your mushroom models :-). TG can handle lots of polys if your machine has the resources for it. It's no problem in populations, although it is a little wasteful for objects which are further from the camera.

I believe we have per-object raytracing scheduled for the near future so you will be able to choose whether an object/population renders with RTO on or off. You could have buildings and hero plants rendered with it off and populations rendered with it on.

Regards,

Jo

[TheBadger]

Hi Jo thanks for some good words!

I hope you don't take my OP as a complaint, Im really not trying to beat an old dog. I know you guys are working and Im sure you'll get things just the way you like em'.

But how I did the mushrooms will not work for things like I meant in my OP; grass, bushes and the like. And even if it would it would be crazy!

What I have been thinking is, if the practical effect of RTO off is to cause parts of a model to look less lush (branches and leaves disappear) THen shouldn't I simply add more branches, leaves, blades, but not increase the over all polly count? That is, not make the model higher res, but just make the plant more dense in terms of number of parts?

Is this not reasonable? Or do I still misunderstand the nature of the issue?

I look forward to the final fix. But in the meantime I have to model some plants anyway, and I'm trying to do it in a way that will work best across the board.

[jo]

Hi Michael,

I think that might be a bit backwards. From what I recall having RTO on will make vegetation seem less dense. It's not due to the models, it's due to the rendering. RTO off tends to look somewhat blockier. RTO on is more accurate so more closely shows the actual shape of the polygons and is better at picking up fine detail. It's also a lot faster.

I'm not sure you can make models which have the same appearance, or rather silhouette because that's what we're talking about here, using both rendering methods at the default settings. The reason I emphasise that is because you can make RTO off look like RTO on if you increase the render quality settings. The thing is you have to increase the render quality settings quite a bit to match the quality of RTO on.

It's been a long time since I did the first tests to compare visual quality between RTO on and off, so I don't remember the details exactly. I seem to recall that to get the same visual quality with RTO off to RTO on at the default settings you needed to bump the render settings until the RTO off render took 5 to 6 times longer. It might be a different story today with more control over sampling and such, one of the others would need to answer that.

For grass and bushes it seems to me these are perfectly suited to rendering with RTO on because you're not so likely to need displacement maps for added detail with those. Bump mapping would probably do. When we have the ability to choose RTO settings on a per object basis then you could render trees with displacement maps for bark etc. using RTO off, but render things like grass and bushes with RTO on.

I don't think this is something you can address with models. I mean, maybe you could try making leaves a bit smaller and blades of grass more slender to allow for the fact that RTO off at default settings is a bit blockier, but it would be something you'd have to experiment with yourself. I have no idea if it would be worth pursuing and I don't think it'd be something I'd do.

I believe the plan is to have per-object RTO in the not too distant future. This should allow you to make the best compromise between speed of rendering and using displacement on models. I think it would be better to produce models with that in mind, rather than find you have to redo them down the track.

Regards,

Jo

[Dune]

I believe the plan is to have per-object RTO in the not too distant future.

That would be an enormous step, guys! And what would be even better is to have the ability to have RT also depend on distance! Pop of trees, e.g; set it to RT off for close instances, RT on for distant instances. Don't know if that's feasible though (software-wise).

[reck]

Will there ever be a time when we won't have to make a choice and be able to render with displacements and raytracing or is it just not technically possible?

[Oshyan]

Reck, displacement on objects with "raytracing" is technically feasible, but will take a good deal of under-the-hood work in the renderer, so it will be a while before it's possible unfortunately. In the meantime the per-object raytracing option should help.

- Oshyan