Non-Raytraced, Environment Map Only Reflections with Car Pai

[chepmedia]

Is there a way to tell the Car Paint shader to reflect only a bitmap enviroment and not raytrace, similar to the way shaders like Phong and Lambert have a pulldown under Reflection that says "Raytrace" or "Environment"? Trying to cinch up some render times.

[SpookyMunky]

The easiest way I can think on right now would be to just split it into two passes.. For the surfaces that have car paint just disable reflection by setting to 0,0,0 / black in their surface reflection tab then create a new pass (Render-Pass-Edit-New Pass-Empty), and open up explorer. Now change explorer's view to passes, expand the newly created pass and select the background objects partition, create a constant black material for it.

Next select the objects that have the car paint shader and create a new partition (Render-Pass-Partition-New Partition). With the new partition still selected create a new material.. phong / lambert / whatever.. open up render tree for it and you want to add the same enviroment node and texture your default / render pass has.. you can recreate it or select the pass in explorer and refresh render tree, right click the enviroment node and copy branch.. re-select the partition and refresh render tree.. connect. Finally disable diffuse and specular in the partition's shader node and enable reflections, set to enviroment only... personally I'd add an incidence node going into a gradient to control the reflection, with enviroment only the impact should be 0.

To composite is just a case of setting the rendered reflection sequence layer to screen, rendering in 32bit exr or something I think is best.. give you a bit more room to dial in the reflection you want using levels / hls etc..

Sorry if this is a really bad explanation, can make a vid if you want... also inversely sorry if some of this is pointing out obvious / patronizing ..figured might aswell explain some of the steps in case it helps someone .. also this is just how Id setup a render pass purely for enviroment reflections, in no way meant to be a solution for a "proper" reflection pass

A nice single pass way to do this without editing the shader etc I would appreciate if someone knows .. my initial thought was one of the ray switch nodes I use to speed up fg heh.. hmmm

[Mathaeus]

there's also a "brute force" way, just to set the reflection depth to zero, in global render options. However I think this works only with main ray-trace reflection of Car Paint, bit not with ray-traced flakes. Not with MIA, too, if I'm correct.

Of course, mixing could be done directly in render tree, something along line of old Master Zap tips - he did reverse, forcing the MIA to behave like Car Paint, but no big deal to mix some shader with environment only reflection, over Car Paint without any reflect.

[SpookyMunky]

I know this isn't my thread but thanks mathaeus , I figured I must've been missing something obvious, usually am!.. phong with diffuse and spec disabled and ref enabled and set to enviroment only going into a the foreground of a toon mix node set to screen, with car paint that has reflections disabled as the background looks pretty much the same as 2 passes and compositing, rock on

http://i.imgur.com/vd0GSZy.jpg

the torus on left is car paint with phong env reflections.. the one on right Is just car paint... needs to be dialed in a lot to match perfectly.. am sure it can be done tho, very cool, love learning new tricks !