Uniformly lit Iray render?
Oso3D
Posts: 14,897
in The Commons
I'm trying to get renders where everything is evenly lit -- no shadows, no occlusion, nothing. Just flat color.
I've been poking at Interactive mode, but despite shutting off shadows in render settings, shutting off the object's 'shadowcasting,' and everything... there's still obvious lighting involved. I tried turning off the normal lighting, but then everything is black.
Any ideas?
(I COULD go through and move all the diffuse channels to Emission channels, but I'd REALLY rather avoid that, if possible)
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You didn't happen to get lucky and grab those excellent HDR lights from MEC4D did you? She posted 3, ambient, outside ambient , and Studio.I'm looking for the link to the post, but I'm sure the time has expired for the downloads.
I did, but those still have issues. Although if I make everything not cast a shadow... hrm...
EDIT: AH HA! That did the trick.
Making a dome uniformly white, and make sure everything doesn't cast shadow.
For the curious, I'm working on my postprocessing technique to make my comic. Trying to layer drawn and shadow layers on top of flat color value, so I'm trying to get a render shaded properly and then a render with flat color.
\(-_-)/ Yay :)
Greetings,
Hrm; I would bet you could do that with Light Path Expressions and output buffers...
-- Morgan
We've talked about using a uniformly shaded 8-bit TIF for the Iray Environment in a couple of threads -- you participated in them, so I'm surprised you forgot so quickly!
However, I would recommend you use a neutral gray, and then adjust the Environment Intensity as needed. When you make it gray, you have more latitude in adjusting the scene levels.
Huh. I am a bear of very little brain. ;) Thanks for the suggestion.
If you don't want occlusion or shadows or anything that Iray is meant to do wouldn't it just be simpler to use 3delight and with ambient light. If it is just the model you want to be flat you could always render the model in 3delight seperately and then the background with Iray.
Because then I'd have to retexture everything with a goal toward getting something nearly identical, but without lighting. Which would be a real pain.
Yup. Sometimes it easier to pound the nail into the wall with the handle of a screewdriver rather than heading back to the garage for the hammer...
TD
Since you're doing a pass for the shadows, that requires Interactive mode anyway. You might as well render in that mode, and have full control over shadow cast and catch. That way you can do a single render and get all the canvases at once.
You could render it 3Delight with all surfaces using DAZ Default shader and put the textures in the Ambient channel. No need for lights and it will render quite fast.
Jestmart: The key is trying to get a color render of the regular Iray surface. If I start mucking about with alternate shaders, that balloons out my workflow enormously.
However, one thing I'm finding is that if I am careful with tonemapping, I can make a more even image to work with, which is a lot easier.
As an experiment I went into pant.net and created a 512x512 white square and saved it as a png. I plugged that ino the iray environment map where an HDRI would normally go. Headlamp off and no other lights in scene. I then made a small plane and a sphere, the sphere had a coloroed checkerboard applied. With the even white lighting the image was really blown out so I adjusted the environment intensity from 2 to 1. I got this.
I did another render, this time with some more interesting geometry, a bunch of props on the plane. I also turned down the plan's gloss and reflectivity to get rid of the slight reflection. Still some shadows but best I could come up with.
Yeah, that fits some of my experiments.
Another thing to watch out for is reflections.
I'm with Tobor...the best results I've had are a mid-grey or gradient from a dark grey to a light grey (not to pure white...about 60 RGB to 204 RGB) and keeping the image 2x W vs H (1024 x 512)...
You don't even want reflections? I guess there's a diffuse canvas pass that won't have highlights and (I think) reflections, but the way it works will probably make everyone look like souless zombies with black eyes, unless you alter the eye surfaces shader. You might instead try taking Max Path Length from -1 ("infinite") to 0. I've never done that, and it may not even work, but you could try. You could certainly remove two-bounce reflections with a setting of 1.
That said, given what you want to do (drawn look, etc.) I wonder if Iray is the right renderer for all this. 3DL has a lot of flexibility here, including drawn-style shaders.
In the early 80s I worked for a government defense contractor doing macrophotography of machined parts. What I would have given for a light tent with this kind of diffuse lighting. One day my boss freaked out when he opened the door to my office and saw this 3-foot white cube on my desk -- he thought the company had been overrun by aliens or something!
Today, it's a matter of grabbing the SolidWorks model, (converting it to OBJ of course), and rendering it CG. Hence my interest in Iray...
Tobor: Well, I'm finding I want two separate things -- a mostly 'gray' or minimally lit 'just show the objects' for good edges, and then an image where the color shows sufficiently to use through the entire range.
In the first case, removing a lot of maps and making everything a relatively flat gray does well, though I have to be careful about reflections, glows, and so on. In the second case, the trick is making sure the color range is visible and not overly shadowed or blown out. Tone mapping and lighting does a good job there.
I'm getting what I need most of the time, so I'm good. ;)
Pretty please, could you find the link?
Edited to add: I found one of the messages - and you are right, the download has expired. Sniff