HQ grass 1 [w/vray-mtls] comes out too dark

[Jon Berntsen]

Hi folks.

 

I've been using the HQ Grass1 models (http://shop.cgarchitect.com/models/plants-and-trees-models/hq-grass-1.html) for a while, but I just noticed one thing: I have suddenly no reflections on it in my VRayRawReflection pass. I saw this after some troubleshooting for finding out why my grass is always too dark compared to the rest of the content of my scenes. I found that "trace reflections" (and trace refractions) was unchecked in the Options part of the material. Does the v-ray material package come with these parameters turned off, or is this something that I did?

 

As mentioned, I'm looking into why my grass is too dark. Eighter it's my lightning somehow, or my materials... I'm using HDR's for lighting, specs and reflections.

 

Anyone else seen this, or been looking into this before?

[Stephen Thomas]

This is usually a way to reduce render times on objects that don't really need an accurate reflection of the scene. It will still pick up a specular highlight from your lights which will be seen in the specular render element. If it is rendering too dark you could try increasing the receive GI amount on the grass object through vray properties. Or just lighten the diffuse colour.

[Jon Berntsen]

Thanks for your response! I suppose the GI solution will decrease the render times a bit from trace reflections, but not as great as if it all was well balanced in the first place (and no need to compensate). Might be just me wanting the grass to be brighter than natural. All reference photos comes with different light conditions and exposures, and maybe I want some from multiple images to achieve the targeted mood. Eighter way, I am going to find my personalized solution to it. 1) Lighten diffuse, 2) Duplicate hdr which includes only a shadow dummy and the grass, or 3) Increase GI on the grass. Most natural to think of the brighter diffuse as the fastest solution, so that's the one I will try. Thanks again.