LOST with emissive materials -.-

[N3MES1S]

Hi guys, im trying to make a emissive material but i cant get it to work propertly with the difusse texture . I tried creating an emissive material from scratch, and i tried loading an already created for vray emissive material. Everything seems to be fine, i got 3 layers, the diffusse, the emissive and the reflection. But it doesnt matter wat layers / options i modify, i cant get the light and the difusse to show up in the render at the same time. I always get a blank spot in the place where the texture / difusse map should be. So my question is... how to make an emissive material with a difusse texture layer??? as i noticed, i can only get to work a emissive material with not difusse mapping. Any ideas??

[arqestevez1]

Re: LOST with emissive materials -.-

hello my friend... the thing here is that you have to use a map for the emisive material... i mean in the emisive layer...
also, now we can move the order of the layers within every material, so be sure that you're not leaving anything important at the bottom

[andybot_cg]

Re: LOST with emissive materials -.-

I would also check face orientation... If the material is not double-sided - it will only emit light on one side, and you may be looking at the back side of the material if it is black.

[N3MES1S]

Re: LOST with emissive materials -.-

I would also check face orientation... If the material is not double-sided - it will only emit light on one side, and you may be looking at the back side of the material if it is black.

Yea already checked that. The main problem is that i really dunno how to check if the emissive material is emitting light or not. In the final render i cant see any extra emiting light, even if i put the intensity , for example to 1000. I put the difusse layer the first and the emissive layer the second. Is that correct? If i want only a color for the base difusse channel (not a texture) and i select, for example the yellow color in the color box, and i put an emissive layer with yellow light in second place ?? that will work??. Cuz as i said, i cant see any extra light emiting from the yellow material or maybe it is just the illumination that is not matching theenvironment, but still... any way to "check" for real if any material is producing emissive light?

[andybot_cg]

Re: LOST with emissive materials -.-

ah - there's the problem. Emissive has to be the topmost layer. If not, it's getting "hidden" by the diffuse layer.

[N3MES1S]

Re: LOST with emissive materials -.-

ah - there's the problem. Emissive has to be the topmost layer. If not, it's getting "hidden" by the diffuse layer.

Yea thx, i figured it out by looking at others pre-made vray materials, but still it seems that the light emited from the material is almost none... i needed to put some plane vray lights to make those areas lighten, cuz i cant get the emissive materials to turn into "emissive" for real lol..

[andybot_cg]

Re: LOST with emissive materials -.-

Well, if you are using sunlight for your scene, the emissive intensity has to be very high to show up at all. I usually only do emissive materials where the sun is turned off. (interior scenes or GI)

[N3MES1S]

Re: LOST with emissive materials -.-

Hi, well i thought i already mastered the emissive materials, when i encounter the same problem in another model. And now, im defnitely lost, i checked the physical camera, and all the layers are in the right place, it doesnt matter wat intensity i put (i tried 300000 lol and nothing happens) no emissive light is getting out the material. Since it doesnt matter wat tutorials i read (all of em are unspecific and doesnt talk anything about the things u need aware when u create emissive materials) , cuz even following the instructions, i cant get an emissive material. IS THAT HARD on VRAY?? I only achieved once, and i copied the same material to the other model... and lol, surprise, it doesnt work in the other model. Even if i didnt change anything. Some points i dunno how to chekc -> the sunlight on sketch up, since its always on (i dont know how to turn if off) and i dunno how to check it on vray, i dunno if i need to check "default lights" to avoid using sunlight from sketchup.

Im completely lost, cuz this seems that emissive materials are randomly effectiveness.

Is there any good emissive turorial i can read?? (not the official vray one plz, i didnt learn anything from it).

Now im trying to make a starship engine that emits light (of course) but just a emissive light. So placing a rectangle light in front will be useless cuz the light needs to emanate from the engine. In the other model i have, i did it perfectly, but now i cant even get the engine to emit any type of light. Even if i didnt change anything in the material. :-[

[andybot_cg]

Re: LOST with emissive materials -.-

note that there is currently a bug where material layers do not copy over from one file to another if you copy and paste. You may need to save your emissive material that is working to a vismat file, then load it in the vray materials editor in your destination file.

[N3MES1S]

Re: LOST with emissive materials -.-

note that there is currently a bug where material layers do not copy over from one file to another if you copy and paste. You may need to save your emissive material that is working to a vismat file, then load it in the vray materials editor in your destination file.

Of course that is wat i did, i saved the material as a vismat file and loaded in the new model. And it doesnt work..

[andybot_cg]

Re: LOST with emissive materials -.-

Sorry to hear you are running into problems with it.
What are your environment and your camera settings? Did you also try saving your visopt settings from the model that was working? Emissive materials put out very little light, and if your environment light is too strong, the emissive light will not show up.

[andybot_cg]

Re: LOST with emissive materials -.-

If it would help, here is a test scene I did a little while back with emissive materials. This was to figure out what lighting and other settings work best to use in a larger scene.

skp test scene