I have a scene (for now just an image not a video) that I want to add my droid to. However, I’m having some problems on the realisticness of the cg character.
I think the two main problems are 1. lighting and 2. the sharpness of the cg character.
I first added a sun lamp in the position of the sun on that day. The sun was near the top of the sky but slightly infront of the characters producing a slight backlighting. Adding that lamp resulted in the droid’s closer side not being visible because no light was hitting it. So I added a second less powerful sun lamp going in the other direction to provide fill in light. However, the material that I gave the droid is supposed to be smooth and shiny and thus is getting glare marks from the second sun lamp when it really shouldn’t be. I’m happy with the shadows produced from a shadows only spot lamp. Is there any way I can make the whole scene lighter by default so I don’t have to add the second lamp? Or is there a lamp setting that will make the light more diffuse? Any other suggestions welcome.
The crisp sharpness of the cg character looks rather unrealistic. My current idea is to leave it as is and when I composite it with AE, add a slight blur to the cg character. Does that sound right? How do most go about this?
Are there any tut’s available on how to effectively add cg to live action video and make it look beleivable?
First off, I think you need a much sharper image for the background. The current one seems very pixelated at that size… Second, you could apply a bit of a motion blur to the CG’ed object to make it look like it belongs. I think also the CG’ed object looks a bit dark for the scene. maybe try to add some lights around it for a brighter look… Hope that helps.
Thanks. The background image looks low quality right now because I used a lower quality jpg file as the render backbuffer in blender. The actual video that it will be compoisited on is much better quality.
Motion blur will blur the object while it is moving but what about when it is stopped?
Also, I tried adding other lights but since my droid’s material is shiny, it produced glare spots on the droid that really shouldn’t be there considereing where the sun was. Is there any other way to do this?
I was able to lighten it a little without glare spots in the wrong place by adding some ambient light from the world.
Hmmm… maybe whenever the droid is stopped you could have it continue to bob up and down or rotate a bit so you can still use the motion blur effect. As for the lights, I understand the problem with the light shining in the wrong places so maybe you could just increase the Energy of the main light or add another light at the same basic location as the main light and increase the energy in that. Hope this helps…
If it were me, I’d render it nice and sharp, then do the post and composite in AE. In AE, through a little noise layer on top of it, blur the whole thing by .5 pixels or so and cut the color saturation way back.
As for more lighting, You should think about rendering your droid with a faked GI dome. It’ll look great. But highlights on the object, you say! If you want to make it look shiny, putting a texture map set to refl mapping for a faked, subtle reflection would go a lot further toward making it appear shiny than any combination of specular/hardness settings. Turn your spec way way down, add a refl mapped texture using your animation frames as the image.
I understand the AE stuff with no problem. I’ll give that a try.
The lighting. Still a little confused. What exactly is a faked GI dome? How do I make/use one?
I think I understand about the Refl texture. Correct me if I’m wrong. This would give me a slight reflection of the grass and stuff on the droid but the droid would still be black. I black slightly reflective surface, excellent! Unfortunately, I need a little more step by step on this process.
OK add a icosphere around the droid.Cut it in a half. add a light and change it to a spot. parent the sphere to the lamp and go in animation buttun (the one where you had particule system) and click duplivert. now go in the light buttun and put the energy slider down…until you got what you want!
Oh that make sense. Then I get a lamp at each vertex right? Why would I want it to be half the sphere and not a whole sphere surrounding the entire object? Secondly, will that produce a lot of glare on my droid’s material since the spec is set high? Should I reduce that?
Thanks for all the help you guys have given a me on my first ever movie.
1.yea sorry, you can put the whole sphere (when you make a all-3d scene you have a ground so the bottom part of the sphere is not needed!)
2.yea you should reduce the spec. Of what I remember of star wars those flying droid dont have spec. they are black with other texture. tell me if I am wrong!
Another suggestion for lighting, which I usually use, is the following:
Use one HEMI lamp instead of the SUN lamp. Place the HEMI lamp i a somewhat close location as the sun light ion your image. Next, you can rotate the driection of the HEMI and have it pointing in the direction that you want the light to go. Set this to somewhere between 0.7 and 0.85 intensity.
Place about 2-3 Spot Lamps in a circle around the robot at the same height as the HEMI. Set these Spot Lamps to ONLY SHADOW, and have them track to your robot. This will make the shadows that you want, but will not provide any “hot spots/glare” on the robat that you have already mentioned.
With these above 2 items in place, you will get the faked GI sort of lighting effect, without the horrendous render times that this can have.
If you have after effects you have all kinds of options to add realism. Like multipass rendering in blender and then compositing it in AE also feathering the image’s edge.
I tried a few of the suggestions listed here and in BlenderwWars.com forums.
Use a faked GI dome around each droid.
Turned down spec alot. Had to otherwise the GI dome produced “spots”
Add a new texture to the droid that was the background image itself and was set to be a refl texture.
Rendered and composited in AE.
Added a little blur.
Added a tiny bit of noise
Cut down color saturation.
However, it still looks a little off. I think I’m on the right track but just not there yet. I think I went a little too heavy on the Refl texture. Maybe if I turn that down and a bit, put some of the color saturation back in, and maybe try to add a little spec to it again.
The only problem with adding spec to it again is that with the GI Dome (Sphere of DupliVert’ed lamps), it would produce a “spotting” effect.
For the GI Dome, why would I use spot lamps that produce shadows. I really only need the shadows that are currently produced. For my dome, I used a regular lamp. Is this wrong? I don’t fully know what a GI Dome is.
That is definitley much better. You are correct though, it is still lacking a bit. The droids should have a darker, more of a shadow on the right side of them, like the dude in the image. Right now, it looks like there is light coming from everywhere around the droids, which the GI dome would do.
Maybe you could use actual radiosity on them, and then use dotblend’s texturing method to get the GI lighting effect, and then use a spot lamp to generate the shadows? Maybe give that a try.
For the GI Dome, why would I use spot lamps that produce shadows. I really only need the shadows that are currently produced. For my dome, I used a regular lamp. Is this wrong? I don’t fully know what a GI Dome is
OK, the GI dome is there to fake the GI. You need the spot lamps in order to produce the more realistic, and softer shadows that appear in real life. You can set these spots in the GI dome to Shadow Only and then use a standard spot outside of the dome to generate the shadow on the ground.
So the spot lights used in the GI dome are for shadows cast on the object? Then a separate spot light would produce the shadow on the ground?
To get the far side of the droid darker, perhaps I could cut my GI Dome (sphere) in half and just have the half on the side that should be brighter? Possible?
Should I use 1 GI Dome for each droid or one large one for the whole scene? I was using for for each.
What do you think about the reflection stuff on the droid’s material? Options: Keep it as is, tune it down, remove completely, remove and add green lamps from below, remove and try ambient light?
I’m not sure how I could get the ambient light to work. The picture is just a back buffer.
So the spot lights used in the GI dome are for shadows cast on the object? Then a separate spot light would produce the shadow on the ground?
Yes, exactly.
To get the far side of the droid darker, perhaps I could cut my GI Dome (sphere) in half and just have the half on the side that should be brighter? Possible?
Yes again.
Should I use 1 GI Dome for each droid or one large one for the whole scene? I was using for for each.
If you use 2 domes, then it will take longer to render, (I think). One dome should render a lot quicker and I less of a hassle to deal with.
As far as the reflection, I really didn’t notice it at all. So maybe just leave it as is.
With the ambient light, try using a HEMI, as I suggested before. Hemi’s seem to work best, IMO.
