Color background

[haggi]

Hi,

I'm trying to reproduce a behaviour I know from maya. I want to create a simple background color, or something like an infinite IBL node which can be seen in reflections or refractions. I'd like to use a ramp as color input for the environment, not an image or maybe an image but with the possibility to adjust color, brightness etc.

In Maya I can create a simple IBL node, switch to texture mode and connect any shading node into the texture slot. Thats quite conveniant.

In Houdini I can create an environment light and use an image, but I'd prefer a procedural approach. So I can create a sphere, scale it and put an appropriate shader onto it. But this means I have do take care that the sphere does not cast shadows, is always larger than the scene.

So my question is: Is there a way to create a spherical environment shader and connect some nodes to it in a way that it automatically can be recognized in my shaders. Most nodes like the camera or environment light work with texture files only. e.g. the vop_trace() will call a vop_trace_environment() that will evaluate a texture, not a shading network.

I hope the description was not too confuse.

[rafaelfs]

Hi,

I'm trying to reproduce a behaviour I know from maya. I want to create a simple background color, or something like an infinite IBL node which can be seen in reflections or refractions. I'd like to use a ramp as color input for the environment, not an image or maybe an image but with the possibility to adjust color, brightness etc.

In Maya I can create a simple IBL node, switch to texture mode and connect any shading node into the texture slot. Thats quite conveniant.

In Houdini I can create an environment light and use an image, but I'd prefer a procedural approach. So I can create a sphere, scale it and put an appropriate shader onto it. But this means I have do take care that the sphere does not cast shadows, is always larger than the scene.

So my question is: Is there a way to create a spherical environment shader and connect some nodes to it in a way that it automatically can be recognized in my shaders. Most nodes like the camera or environment light work with texture files only. e.g. the vop_trace() will call a vop_trace_environment() that will evaluate a texture, not a shading network.

I hope the description was not too confuse.

You could create a ramp in COP and feed it to the environment light using the expression

op:/img/"your cop network"/"your ramp"

[haggi]

You could create a ramp in COP and feed it to the environment light using the expression

op:/img/"your cop network"/"your ramp"

Thanks, thats a good solution for creating shaders from within houdini, but I'm writing vex shaders for a maya hypershade translator. This means it would be possible to implement cops, but it would be a large overhead.

[3dbeing]

I'm not entirely sure how to implement it but the docs say...

The color from this environment map is returned if the ray does not hit anything. Without a map here, the Background Color, below, is returned when the ray misses.

So it seems you could plug your shader colour in here...

Edited December 27, 2011 by 3dbeing

[haggi]

Yes, indeed if I use the trace vex node I can choose the bg color.

My problem is, that I'd prefer not to set the bg color in all transparent or reflective shaders, but create one bg shader, e.g. a ramp, which will be automatically returned if the ray hits nothing.

Because I create my shaders automatically from maya hypershade, I can make a dummy ibl node and add a environment shader evaluation automatically into every shader... good idea.. thanks.

[3dbeing]

right, so create you bg vop shader inside the same vop shop and plug it's output into the color input.

Edited December 28, 2011 by 3dbeing