appleseed Users Forum

Individual Diffuse/Specular Controls


i’d like to add a request for separate diffuse and specular controls per object or material. that could be either rays or samples and ideally both like for example Mantra and alSurface have it.


Hi @CuRZ4,

some infos about ongoing development and planned features (on GitHub):

You can also join Discord to get in touch with the developers and get immediate feedback:

1 Like

What do you mean with separate diffuse and specular controls per object? can you provide a screenshot please? Honestly I’ve never heard of such thing :DD cheers

oh then you missed a lot. i’ve been using these things for years and they’re priceless. this is what they do:

the ray depth controls are the same as the global ones but just per object. let’s say you have an object for which you want specular highlights but no reflections of other objects. then just set the specular depth for that object to 0. that’s also a nice speed increase in regards to the rendertime.
the same goes for indirect diffuse.
with reyes you could even set how far the indirect rays should travel which is fantastic.

the samples per material is similar. you can increase or decrease the samples for specular and diffuse per material. so you can individually nudge certain objects’ quality without having to change the global settings.

so this a winwin, it not only allows for precise quality control but also gives a speed boost.

Mm I’m not sure to understand ‘separate diffuse/specular controls’. So far it seems to me they are not so needed.

We have this: Visibility flags.

no, the visibility flags are the other way around.

for more info have a look at:


1 Like

I don’t think is needed, how would you use it? on a practical scenario?

I think it makes sense as a feature, @CuRZ4 gave one practical scenario in his post above.

1 Like

well these features have been around for years, are well known and very useful. if you didn’t get it by now just fire up houdini and check it out. or renderman or mental ray or arnold … they all have at least one of them.
after all this is a feature request and not a tutorial :stuck_out_tongue:

Oh, that’s rude. Thanks

and turning something down just because you don’t understand it is better? :wink:

anyway, you did notice the smilie at the end, right? that was meant as a hint, with a touch of irony, to tell you exactly that.
so again, if my examples were not enough, just try it out with a product of your choice that has the features in question. it obviously makes no sense to judge something you don’t know.

Honestly, I don’t understand why are you acting like this. I’m not experienced and obviously I don’t know how to use it. I’m really confused.

Lucky for you I’m not a developer and neither not the one in charge, so I don’t get to decide what’s implemented in appleseed and what’s not.

that’s no problem but statements like:

make no sense then.

Guys, please relax. Communication on the internet is hard so please assume best intent from all parties.

The feature request is clear, thanks.

We’re discussing internally whether this is really something we want in appleseed. I would tend to think so, but in a path tracer, and even more so in a bidirectional path tracer, this kind of fine control over bounces is not necessarily desirable, or may simply not work at all.

more than happy to get back on topic.

it does work with bidirectional approaches. renderman’s ris (vcm integrator) shows that.

however, the ray depth was only one suggestion. if another way leads to the same result it’s just as fine. or maybe something with a similar effect at shader level … you get the idea. the key is to have local overrides of the global settings. how and where this is done doesn’t matter as long as the control is there in some form.

Do you know if Arnold supports such ray depth overrides?

arnold doesn’t have depth control but it has controls for indirect intensities. see the last 2 paragraphs there

the 3rd party alShader had extra sample settings in addition for indirect diffuse and specular.