I have three lights with r,g,b color set, when I enable this mode, the render ignore light color,
something I am missing?
No, Version 1.5.0 changed the way Additive mode is calculated, so this is As Designed.
Since we added Emission and Absorption, Additive mode is a variation of Volumetric mode where the Color channel is copied to the Emission channel, while Color and Absorption are set to black. The result is a fully emissive rendering that ends up additive. But since the Scatter Color is black, no light is being scattered from light sources into the eye, all the energy is coming from the Emission channel. So it is like trying to illuminate a 100% self-illuminated object - it is already illuminated and no light is reflected from the lights.
The added benefit from this is that you can mix volumetric and additive shading per particle in any proportion:
software.primefocusworld.com/sof … hading.php
In earlier versions (1.1.x), Additive mode was a separate rendering path that did not support volumetric shading and we decided to allow the illumination of particles. If you really have to do that, you might try running an older build.
thx clear exp!
hi, BoBo
I back to ver1.1, but the additive mode calculating result is not the same as 1.5
I have a scene already setup with ver1.5,and i dont want to re-treak parametres in 1.1, so is there a way to bake light’s color to emission channel ?
In 1.1.x, you can get some lighting into the additive rendering, but it lacks half of the features of 1.5.x (as the version number implies).
In 1.5.x, you cannot get additive rendering (which has no alpha) scatter light, and if you blend into volumetric shading, you will start getting attenuation of light (shadows) and alpha (see that tutorial). So you could try to get some intermediate state that is mostly additive but with a shade of … shading.
Also in 1.5.x, you can bake volumetric lighting into the Emission channel while saving (that will also contain the attenuation). You could bake that to PRT, then reload in a PRT Loader, set Color and Absorption channel overrides to black and render - that will be additive. See this page and especially the end of it:
software.primefocusworld.com/sof … saving.php