Need Help getting started with 3Delight...

[Kerro Perro]

Very much related to my thread about "artistic lighting" i am trying out 3Delight. I must say the speed and the look and feel of it blows me away - i really think this the type of renderer i need for my NPR desires, now if only i understood it's workflow...

I'm already stuck on two things:

-the first one is fairly simple, i notice you need to change code in the shaders sometimes so i pick it in the render tree, choose "edit shader", paste the code and click "save as". SI tells me it needs to restart in order for the shader to work so i do. Well here's where my noobness once again rears it's ugly head because i don't know how to get the new shader/.spdl in the render tree. I tried installing it through the plug-in manager but it won't install and it won't drag and drop anywhere either..

- the other is more complicated and i think goes to the heart of the 3delight workflow compared to other renderers: the way you use 3delight properties... (i mean those you get from Property > 3delight > ... not the ones in the renderer options) I tried to set up an AO pass with the point based AO i read about but i can't for the life of me even find the tabs and propeties described here (point 5.5 in the manual) and in this maya thread post #5.

I did do a search for tutorials for this but couldn't find any... I really hope i can learn to use 3delight without having to get to grips with all the Renderman stuff because that always seem sooo intimidating.... (even though i studied computer science i have an aversion to raw code - or maybe because of it ;) )

[Mathaeus]

hi there, just a few very personal comments

First, about differences between Maya and SI plugin. As far as I know, Maya plugin is created from stuff, already used in studios, SI plugin is created more for scratch (even there were some behaviors of old Affogato translator). That is, SI plugin is probably most artist friendly plugin of this kind, ....... in Renderman world . Well, "user friendly" usually means, no every feature of renderer is exposed - or not completely.

About changing the code, I don't believe the user is "supposed" to do that. Anyway if you want, code for almost all shaders is in "rsl" folder of 3delight installation. However messing with code is a *very* risky business, one wrong word can screw up the entire renderer, make it slow, so on.

Point based AO - in latest few versions, AO and GI are both under "GI" (global illumination). So, once you have XSI ambient occlusion connected in render tree, you have to enable "point-based" under global illumination.

Anyway, ray-tracing is faster in every new version - especially if there is no too much of shader calls ( shader call = once ray hits the surface, shader found on surface is activated). In case of AO, there is no any "shader call" - so imho it can be reasonably fast.

Tutorial, docs... as far as I know, the "problem" is similar to ICE - actually is not that hard to get familiar with basics of Renderman shaders, and to do something simple. I'd believe it's somewhat hard to find people, willing to write these tuts.

[Kerro Perro]

Hi Anto, thanks for replying.

Right so you're not supposed to edit shaders huh? Well since my knowledge is way too limited i shan't bother with that then... I read your 3delight tests thread and i thought you talked about "hacking" shaders - but in a quick search i only see you import custom shaders.

I notice that that is done by the use of the 3delight properties i mentioned, as i assume the (cool) CSG stuff, it seems to me that these properties are important parts of the 3delight workflow. I find it odd that there is so little documentation about how to use them.... But as you say that is the same for a lot of ICE nodes...

As for the AO - i got confused because the XSIambientocclusion didn't work in 3delight... Can you confirm that?

And one more thing: am i to understand that the workflow is simply to do AO in seperate pass and comp it later? I have an old Gnomon dvd by Jeremy Vickery (with MR for Maya - but i've done this in SI often:) where he plugs the AO shader in the ambient port to provide ambient lighting....
I couldn't test this with 3delight as the AO shader didn't work but i'm wondering about your take on this method...

[Mathaeus]

Hi Anto, thanks for replying.
As for the AO - i got confused because the XSIambientocclusion didn't work in 3delight... Can you confirm that?

So you're on SI 2013, aren't you. Here is the fix.

In '3delight test" thread, some solution are hacks (like getting the blurred ray-traced reflection, using vertex color as target), some are not, like the last one with "point" type particles.

"supposed" or not, well, just wanted to say, if you're doing the hacks, it's your risk, that's all. Even the hacks of old SPDLs in SI, wasn't free of danger, but we all hacked them... Do backup of shaders first.

[Kerro Perro]

Ah well yeah i found that fix - i linked it in my first post - i just didn't know how to implement it. But now thanks to you i know i need to edit the .sl file in the rsl folder of 3delight. Nice one ;) Oh and yeah i copied the .sl first.

It works but i wouldn't exactly call it fast... I think i prefer MR for a seperate AO pass...

Anyhoo i've got enough to be getting on with, especially since i mostly just want experiment with lighting with many shadow mapped lights. Oh and i found the properties in the manual, they actually are well documented...

I wonder if TAARNA studios gets it's name from Heavy Metal..?

[Falam]

I do have decided to go the route of 3D Delight, slowly migrating to the the render

[Mathaeus]

It works but i wouldn't exactly call it fast...
I wonder if TAARNA studios gets it's name from Heavy Metal..?

Point-based stuff rely on quite different method than firing the rays from surface. Base for searching is angle between surfaces, so it likes more the curved surfaces, instead of flat ones ( that's why furniture is always bended, in Pixar movies ). It also likes a lot of small details as target, like hair or small particles.
You can get it faster by raising the GI shading rate, or "max solid angle", but this can introduce artifacts.
If you want totally non-realistic, over occluded effect, and you like to play with sl files - in XSI_ambient_occlusion.sl, you can change "clamp" parameter from 1 to 0 - this disables filtering of point cloud, so occlusion takes a few more surfaces than it should, also it's about 50% faster.
About shadow maps, if you're using Deep Shadow Maps (detailed, volumic...), by setting the "sub- samples" to 1, instead of default 2, makes it faster too. This disables "up" mip-mapping, while it still can go "down" to lower resolution. Allowed resolutions are power of 2 - 512, 1024, 2048... - nothing in between.

[Kerro Perro]

Hey thanks for the tips i will try them out! I'm currently reading James Gurney's Color and Light to learn more about well light and color ;) Gonna try and mix my painting studies with studies in lighting with 3Delight.

Tonight's experiment: getting a cast shadow to go from hard to soft in a pleasing way - i should be able to just use "umbra" for this i think.
I'll post my attempts in my "artistic lighting" thread.

Edit: Hmm okay i think i may have already stumbled into a limitation to depth map shadows... they seem to be either all soft or all hard... Will make outdoor scenes difficult..