topic Re: environment map as light source in 3ds Max in 3ds Max Shading, Lighting and Rendering Forum

environment map as light source in 3ds Max

Anonymous — Thu, 26 Jun 2014 18:17:04 GMT

I have an light probe image as environment map, I want to render my image at 3ds Max based on the lighting cast by the environment map, so that the environment map can work as a light source. I tried skylight and checked its documentation, but it did not clarify how it works. Is there a way to do so? Thanks.

Re: environment map as light source in 3ds Max

ekahennequet — Fri, 27 Jun 2014 15:41:27 GMT

Have a look at these videos. They may be of help.

Rendering HDRi in 3dsMax

http://www.youtube.com/watch?v=r6mC4uUo4a4

3Ds Max tutorial | Realistic Studio Render with mental ray HDRI

http://www.youtube.com/watch?v=Up6ZhdC-YCE

Re: environment map as light source in 3ds Max

Anonymous — Fri, 27 Jun 2014 18:06:47 GMT

Hi ekahennequet,

Thanks a lot for your reply. The problem I am suffereing now is that I want to use the environment map as the only light source, which can cast relatively strong shadow. Is that possible? It seem in the daylight system, it do have skylight and directional light at the same time, which means we have to have another light source to light the scene. Is that right?

Re: environment map as light source in 3ds Max

ekahennequet — Fri, 27 Jun 2014 20:12:31 GMT

You would need the Skylight, but it will use the "lightprobe" environment map as the only source of light.

I created this image in just few minutes using the hdri image found here. http://www.hdri-hub.com/hdrishop/freesamples/freehdri/item/113-hdr-111-parking-space-free

The only light in the scene is the Skylight using the hdri image in the Map slot. I didn't use the Preset system. I only entered the Exposure value at 2.0. I used the jpeg bg for this, but if you have access to .hdr then that woul dbe even better. You would need to use the same image as the Environment Map. You may need to adjust the Exposure setting and the Skylight's Multiplier settings to achieve the desired result.

Light: 1 Skylight

Renderer: mental ray

Scene objects: Primitive Spheres and a Plane

This page has a quick run down.

http://www.vizpark.com/hdri-lighting-with-3ds-max-and-mental-ray/

Edited: I forgot to include the sample file I created. See attached Zip. I couldn't attach the hdr image file because of the forum attachment limit, but you can download it separately via link I posted above at hdri-hub.com and re-assign it to Skylight and Envrionment Map.

Re: environment map as light source in 3ds Max

Anonymous — Tue, 01 Jul 2014 22:02:34 GMT

Thanks a lot for your reply.

I am thinking whether environment map can cast some strong directional shadow. It seems the shadow you generated (I also generated some similar shadows) are very soft and light. Can we generate some realistic image for sunny day?

Re: environment map as light source in 3ds Max

ekahennequet — Wed, 02 Jul 2014 14:49:06 GMT

Don't think you'll be able to get much sharper shadows using just the hdri envrionment as the only light source.

Good discussion on hdri shadow casting

http://forums.cgarchitect.com/63930-hdri-shadow-casting.html

To get pronounced shadows, I believe most folks use post/composite work using Matte/Shadow/Reflection Material.

http://docs.autodesk.com/3DSMAX/16/ENU/3ds-Max-Help/files/GUID-3F934E37-CC74-4EC7-A0E2-A96A0880CF84.htm

Re: environment map as light source in 3ds Max

Anonymous — Thu, 03 Jul 2014 09:50:08 GMT

> Don't think you'll be able to get much sharper shadows using just the hdri envrionment as the only light source.

Unless you're using quality HDRI, look here:

http://forums.cgarchitect.com/75415-mr-photons-ibl-fg-nothing-thime-better.html

Re: environment map as light source in 3ds Max

ekahennequet — Thu, 03 Jul 2014 15:45:12 GMT

Thanks for that link, blank. Looks like a nice discussion on the topic.