Re: Requesting advice about light object
Hey nevermindI think I got what I need with the mia_lightsurface node piped into the architectural shader, with considerable tweaking Thanks for the ideas! On Jul 5, 2013, at 7:03 PM, Nancy Jacobs wrote: > I'm wondering about the suggested use of the rayswitch node for this. > Especially Matt and Ahmidou suggested it. Do you mean the > mip_rayswitch_advanced? And would I use it to split up the shader influences > on one sphere instead of making the two spheres as in Matt's suggestion? > > Because in your 'old school' method, Matt, which I have been using to light > the scene and create a background, with an hdri and a higher res color image > (seen), there is not the desired glow effect. But it could create light for > the FG, instead of a point light, which may be desirable. > > Any clearer explanations about using the rayswitch node, in this context? > > Many thanks, > Nancy > > On Jul 3, 2013, at 9:46 PM, Matt Lind wrote: > >> Many solutions, but here's an older simple solution: >> >> The object emitting illumination should have secondary rays active, and >> primary rays inactive. This allows rays to be cast for Global illumination, >> final gathering, etc..., but not be directly visible by the camera. This >> allows you to use a constant shaded sphere as the emitter. >> >> The object acting as the bulb and visible to the camera should have the >> opposite settings so it appears in the render, but doesn't block the rays >> cast by the emitter. >> >> You may need to do more subtle tweaking of visibility to account of other >> situations. For those cases I'll refer you to the 'ray switch' node which >> can perform the same task at a more granular level. >> >> Matt >> >> >> >> -Original Message- >> From: softimage-boun...@listproc.autodesk.com >> [mailto:softimage-boun...@listproc.autodesk.com] On Behalf Of Nancy Jacobs >> Sent: Wednesday, July 03, 2013 3:02 PM >> To: Softimage Listserve >> Subject: Requesting advice about light object >> >> Hello, >> >> I've been away from XSi for about two years due to illness, but am back >> working on a project. So, this may be very easy for you guys to answer. I'm >> feeling noobness here, having forgotten so many things! >> >> I'm trying to make a small sphere look like a light source, illuminating >> part of the scene, which is only lit by final gathering and a globe HDR >> object. I'm pretty sure I've done this successfully before, but it's failing >> me this time...;-) >> >> I can't make the sphere a constant material, because I want it to use many >> of the attributes of the architectural shader. In other words, I want it to >> be a reflective ball which is glowing and emitting light. I like the >> simplified emulated reflections i was getting by using optimizations in the >> architectural shader (also the rendering time advantage). So, I tried >> putting a point light inside it, which has somewhat fouled up the nice >> surface I had going with the architectural shader. And there is no >> 'incandescence' in this shader to make it appear glowing. I don't want to >> see the actual point light in the render, but I do want the ball itself to >> be a bit luminous. >> >> I'm also having a lot of trouble with the light attenuation using the >> exponent. Does anyone have any idea how to measure 'Softimage units' in ones >> scene? Do they relate to say, the sphere radius I am using? Or is that a >> whole 'nother thing >> >> Anyone who can give me some ideas or point me to some info about this >> glowing sphere light thing, much appreciated... Seems so rudimentary... >> >> Thanks, >> Nancy >> >
Re: Requesting advice about light object
I'm wondering about the suggested use of the rayswitch node for this. Especially Matt and Ahmidou suggested it. Do you mean the mip_rayswitch_advanced? And would I use it to split up the shader influences on one sphere instead of making the two spheres as in Matt's suggestion? Because in your 'old school' method, Matt, which I have been using to light the scene and create a background, with an hdri and a higher res color image (seen), there is not the desired glow effect. But it could create light for the FG, instead of a point light, which may be desirable. Any clearer explanations about using the rayswitch node, in this context? Many thanks, Nancy On Jul 3, 2013, at 9:46 PM, Matt Lind wrote: > Many solutions, but here's an older simple solution: > > The object emitting illumination should have secondary rays active, and > primary rays inactive. This allows rays to be cast for Global illumination, > final gathering, etc..., but not be directly visible by the camera. This > allows you to use a constant shaded sphere as the emitter. > > The object acting as the bulb and visible to the camera should have the > opposite settings so it appears in the render, but doesn't block the rays > cast by the emitter. > > You may need to do more subtle tweaking of visibility to account of other > situations. For those cases I'll refer you to the 'ray switch' node which > can perform the same task at a more granular level. > > Matt > > > > -Original Message- > From: softimage-boun...@listproc.autodesk.com > [mailto:softimage-boun...@listproc.autodesk.com] On Behalf Of Nancy Jacobs > Sent: Wednesday, July 03, 2013 3:02 PM > To: Softimage Listserve > Subject: Requesting advice about light object > > Hello, > > I've been away from XSi for about two years due to illness, but am back > working on a project. So, this may be very easy for you guys to answer. I'm > feeling noobness here, having forgotten so many things! > > I'm trying to make a small sphere look like a light source, illuminating part > of the scene, which is only lit by final gathering and a globe HDR object. > I'm pretty sure I've done this successfully before, but it's failing me this > time...;-) > > I can't make the sphere a constant material, because I want it to use many of > the attributes of the architectural shader. In other words, I want it to be a > reflective ball which is glowing and emitting light. I like the simplified > emulated reflections i was getting by using optimizations in the > architectural shader (also the rendering time advantage). So, I tried putting > a point light inside it, which has somewhat fouled up the nice surface I had > going with the architectural shader. And there is no 'incandescence' in this > shader to make it appear glowing. I don't want to see the actual point light > in the render, but I do want the ball itself to be a bit luminous. > > I'm also having a lot of trouble with the light attenuation using the > exponent. Does anyone have any idea how to measure 'Softimage units' in ones > scene? Do they relate to say, the sphere radius I am using? Or is that a > whole 'nother thing > > Anyone who can give me some ideas or point me to some info about this glowing > sphere light thing, much appreciated... Seems so rudimentary... > > Thanks, > Nancy >
Re: Requesting advice about light object
Wow, here's a duh momentas that's exactly what I'm doing with the 2 environment spheres, with the visible image and the invisible HDR image! So, i'll try it on a smaller scale for this as well. Not familiar with the ray switch mode, though, I will have to look into that. Thank you Matt. With this I wouldn't need the point light either, as I'm using FG anyway. On Jul 3, 2013, at 9:46 PM, Matt Lind wrote: > Many solutions, but here's an older simple solution: > > The object emitting illumination should have secondary rays active, and > primary rays inactive. This allows rays to be cast for Global illumination, > final gathering, etc..., but not be directly visible by the camera. This > allows you to use a constant shaded sphere as the emitter. > > The object acting as the bulb and visible to the camera should have the > opposite settings so it appears in the render, but doesn't block the rays > cast by the emitter. > > You may need to do more subtle tweaking of visibility to account of other > situations. For those cases I'll refer you to the 'ray switch' node which > can perform the same task at a more granular level. > > Matt > > > > -Original Message- > From: softimage-boun...@listproc.autodesk.com > [mailto:softimage-boun...@listproc.autodesk.com] On Behalf Of Nancy Jacobs > Sent: Wednesday, July 03, 2013 3:02 PM > To: Softimage Listserve > Subject: Requesting advice about light object > > Hello, > > I've been away from XSi for about two years due to illness, but am back > working on a project. So, this may be very easy for you guys to answer. I'm > feeling noobness here, having forgotten so many things! > > I'm trying to make a small sphere look like a light source, illuminating part > of the scene, which is only lit by final gathering and a globe HDR object. > I'm pretty sure I've done this successfully before, but it's failing me this > time...;-) > > I can't make the sphere a constant material, because I want it to use many of > the attributes of the architectural shader. In other words, I want it to be a > reflective ball which is glowing and emitting light. I like the simplified > emulated reflections i was getting by using optimizations in the > architectural shader (also the rendering time advantage). So, I tried putting > a point light inside it, which has somewhat fouled up the nice surface I had > going with the architectural shader. And there is no 'incandescence' in this > shader to make it appear glowing. I don't want to see the actual point light > in the render, but I do want the ball itself to be a bit luminous. > > I'm also having a lot of trouble with the light attenuation using the > exponent. Does anyone have any idea how to measure 'Softimage units' in ones > scene? Do they relate to say, the sphere radius I am using? Or is that a > whole 'nother thing > > Anyone who can give me some ideas or point me to some info about this glowing > sphere light thing, much appreciated... Seems so rudimentary... > > Thanks, > Nancy >
Re: Requesting advice about light object
These all sound like good ideas... I did try out the mia light surface shader, and got a bit closer to what I want, but i'll definitely check all these ideas out next work session. Thanks! On Jul 3, 2013, at 10:42 PM, Rares Halmagean wrote: > Another solution Nancy, may be to composite a render of the constant shaded > material over your architectural sphere depending on how comfortable you are > with approach. > > Or a simpler solution than the one I suggested earler comes to mind; Use a > mix_2_colors node by plugging the architectural shaders out into mix2color > base_color input, plug the lambert or constants out into mix2color color 1 > followed by mix_2_colors out to surface input of the material node, making > sure to dial the constant node contribution via the weight rgba in the mix > layer of the mix_2_colors node. That way you maintain the architectural > material surface properties and mix in the incandescent property of the > constant shader. You may have to play around with the architectural shader > diffuse, reflection properties and mix2colors mix layer properties till you > get the look you want. > > > > -Rares > > > On 7/3/2013 8:46 PM, Matt Lind wrote: >> Many solutions, but here's an older simple solution: >> >> The object emitting illumination should have secondary rays active, and >> primary rays inactive. This allows rays to be cast for Global illumination, >> final gathering, etc..., but not be directly visible by the camera. This >> allows you to use a constant shaded sphere as the emitter. >> >> The object acting as the bulb and visible to the camera should have the >> opposite settings so it appears in the render, but doesn't block the rays >> cast by the emitter. >> >> You may need to do more subtle tweaking of visibility to account of other >> situations. For those cases I'll refer you to the 'ray switch' node which >> can perform the same task at a more granular level. >> >> Matt >> >> >> >> -Original Message- >> From: softimage-boun...@listproc.autodesk.com >> [mailto:softimage-boun...@listproc.autodesk.com] On Behalf Of Nancy Jacobs >> Sent: Wednesday, July 03, 2013 3:02 PM >> To: Softimage Listserve >> Subject: Requesting advice about light object >> >> Hello, >> >> I've been away from XSi for about two years due to illness, but am back >> working on a project. So, this may be very easy for you guys to answer. I'm >> feeling noobness here, having forgotten so many things! >> >> I'm trying to make a small sphere look like a light source, illuminating >> part of the scene, which is only lit by final gathering and a globe HDR >> object. I'm pretty sure I've done this successfully before, but it's failing >> me this time...;-) >> >> I can't make the sphere a constant material, because I want it to use many >> of the attributes of the architectural shader. In other words, I want it to >> be a reflective ball which is glowing and emitting light. I like the >> simplified emulated reflections i was getting by using optimizations in the >> architectural shader (also the rendering time advantage). So, I tried >> putting a point light inside it, which has somewhat fouled up the nice >> surface I had going with the architectural shader. And there is no >> 'incandescence' in this shader to make it appear glowing. I don't want to >> see the actual point light in the render, but I do want the ball itself to >> be a bit luminous. >> >> I'm also having a lot of trouble with the light attenuation using the >> exponent. Does anyone have any idea how to measure 'Softimage units' in ones >> scene? Do they relate to say, the sphere radius I am using? Or is that a >> whole 'nother thing >> >> Anyone who can give me some ideas or point me to some info about this >> glowing sphere light thing, much appreciated... Seems so rudimentary... >> >> Thanks, >> Nancy >> > > -- > Rares Halmagean > ___ > visual development and 3d character & content creation. > rarebrush.com
RE: Requesting advice about light object
Many solutions, but here's an older simple solution: The object emitting illumination should have secondary rays active, and primary rays inactive. This allows rays to be cast for Global illumination, final gathering, etc..., but not be directly visible by the camera. This allows you to use a constant shaded sphere as the emitter. The object acting as the bulb and visible to the camera should have the opposite settings so it appears in the render, but doesn't block the rays cast by the emitter. You may need to do more subtle tweaking of visibility to account of other situations. For those cases I'll refer you to the 'ray switch' node which can perform the same task at a more granular level. Matt -Original Message- From: softimage-boun...@listproc.autodesk.com [mailto:softimage-boun...@listproc.autodesk.com] On Behalf Of Nancy Jacobs Sent: Wednesday, July 03, 2013 3:02 PM To: Softimage Listserve Subject: Requesting advice about light object Hello, I've been away from XSi for about two years due to illness, but am back working on a project. So, this may be very easy for you guys to answer. I'm feeling noobness here, having forgotten so many things! I'm trying to make a small sphere look like a light source, illuminating part of the scene, which is only lit by final gathering and a globe HDR object. I'm pretty sure I've done this successfully before, but it's failing me this time...;-) I can't make the sphere a constant material, because I want it to use many of the attributes of the architectural shader. In other words, I want it to be a reflective ball which is glowing and emitting light. I like the simplified emulated reflections i was getting by using optimizations in the architectural shader (also the rendering time advantage). So, I tried putting a point light inside it, which has somewhat fouled up the nice surface I had going with the architectural shader. And there is no 'incandescence' in this shader to make it appear glowing. I don't want to see the actual point light in the render, but I do want the ball itself to be a bit luminous. I'm also having a lot of trouble with the light attenuation using the exponent. Does anyone have any idea how to measure 'Softimage units' in ones scene? Do they relate to say, the sphere radius I am using? Or is that a whole 'nother thing Anyone who can give me some ideas or point me to some info about this glowing sphere light thing, much appreciated... Seems so rudimentary... Thanks, Nancy
