problems with HDRI

[kpavlov]

I have rendered this car using HDRI made in VUE and there are no other lights in the scene.
Why do I have this artifacts like splotches in rendering.

[Morbid Angel]

splotchiness is not the hdri's fault, but the irradience map which emits it. If you turn off gi, and place this hdri into dome light, you will get better result.

[kpavlov]

Thanks, but this is just a test and I would like to use this HDRI in my scenes together with GI. What is solution for that.
If I understood you, I have to chose GI or HDRI and I cant have both.
Its hard for me to belive that or I have misunderstood you.

[Morbid Angel]

not at all. You can indeed use hdri with gi, if you use irradience map. However, because hdri has a lot of range of data, it will produce splotchiness. The solution is simple: increse irradience map quality. This will remove the splotchiness.
But, if you are smart about this, use dome light to emit hdri direct rays, then use gi to compute secondary bounce. This way you will get precision and good quality from hdri, and good bounce from gi....

[RErender]

I would use two HDRI's one in the reflection override and another in the dome light, the one in the dome light can be sampled down to 300-500 should smooth out the lighting

[studioDIM]

or simply have the dome light included in the irmap calculations.
This will give you the importance sampling minus the direct GI.

Lele

[jujubee]

There was also a problem with HDRs created in Vue not lowering in values below 0 (clamped.) Hence, that was never a viable solution for me. Perhaps you've had better luck?